ERA is a poor judge of a pitcher's ability. Lannan posted a 3.70 last year. His FIP was slightly above 4. And when you compare Lannan's 2011 with Detwiler in 2012, they are remarkably similar:
Lannan: 10-13, 184 innings, 3.70 ERA, 4.28 FIP, 5.17 K/9, 3.70 BB/9, 54.1% GB, .73 HR/9
Detwiler: 10-8, 164 innings, 3.40 ERA, 4.04 FIP, 5.75 K/9, 2.85 BB/9, 50.8% GB, .82 HR/9
Detwiler was better, but not by a whole lot. Frankly, I think the gain of having a better bullpen offsets it. Especially since I think Lannan will be improved in 2013. He showed improvement in limited starting time this season. I also think Detwiler over-achieved this season. His BABIP against was .263, which was the 10th best in baseball. I don't see him sustaining that long term, especially as the NL gets more scouting on him and realizes he's basically a one pitch pitcher.
I posted what I think it would take to get Price. It's pretty hypothetical, but it's at least enough to get the Rays to listen instead of laugh and hang up.
JZ has 1 inning in relief in which he was clearly amped. He's also one of the better starters in the league, so I expect him to look really good. And I wouldn't be against signing Greinke and converting JZ to a closer role if we needed a closer.
I seriously doubt Madson would come here, even if he's looking for a one year, proof of worth deal. Why would he? His only chance of closing is if Storen gets hurt. Meanwhile, there are several teams that will be looking for a closer this season and be willing to spend. God knows the Angels need bullpen help. White Sox may be looking for a closer for the next two or three years until Addison Reed is ready. And the Tigers .... well, I seriously doubt they bring back Valverde. Those are three teams that are not only competitive, but will offer big money AND give him the closer role. One of these things the Nats won't do .... 
The Tigers have been in their peak for a year now. The Nationals are just entering theirs. Oh and the Tigers went and gave Fielder exactly the kind of deal you don't want the Nationals to give out.
There is no way Grienke sings for less than 100 million dollars. Cole Hamels got a 7/150+ extension. It will take that to get Grienke. The Angels have an option on Haren. We'll see if they decline it, but I think he signs for Buehrle type money. I'd much rather give that money to JZ. Certainly don't want to trade him in his prime when we're competing. Which we will be. Teams that are in the hunt for the World Series don't trade away their front line starters.
First off, Det is not a one pitch pitcher. He throws tons of fastballs, but he controls his fastball and sinker all over the zone. He also has a nice changeup and the last few outings, his curveball showed promise of being a good pitch. All ground ball pitchers have high FIP numbers as well. It is inherent because they don't strike out a ton of guys, but put the ball in play and let the defense do the work. Yes, there is no way to say that a good GB pitcher can sustain a very low BABIP, mostly because it does show good luck on the pitchers part that those ground balls are going right at infielders and results in outs. This could change to becoming base hits through gaps. Ross though as he emerges as a GB pitcher can learn how to place his sinkers (he is already starting to do this) in certain spots in the zone to direct a pitch towards a defender, which is how the defensive shift can work so well. Not saying he is a #1 here, nor am I debating that ERA is a flukey stat, but you are also putting a bit too much faith into the advanced SABR stats to identify the worth of a pitcher. Guys like Lannan and Det will be SABR nightmares, Lannan even more so. What Ross has is that pure scouts love that he is a lefty who can throw a 96 mph sinker. This is something you just can't teach, and Det is harnessing the sinker to his advantage by learning to make it a high precision control pitch. If he can do that, he becomes an elite GB pitcher in the game.
I wasn't trying to say that the Nats should give up a 9 year contract to a guy like the Tigers did with Prince, but they did spend because they want to win. If you can lure a guy like Grienke to take a four or five year deal with more AAV, then you should do it. I also disagree that he will get 7/150 or even 6/120. Grienke has a CY, but he also has swings from year to year that don't put him in a class with guys like Hamels or Lincecum (this year non-withstanding). My guess is that his new agent will target this type of deal, but I don't see any team willing to fork over that kind of money for him. 5/100 or 4/85 would be more than enough to get it done I think, but I'm not a GM or an agent. I think you target him anyway and try and make it worth his while to come here as he would be a very nice piece to this rotation, and arguably would be the fourth best pitcher on the team.
As for JZimm, I know you would never intend to put JZimm in the pen. I was trying to stretch out an example of why not to put Det back in the pen. His use as a starter has far greater value than as a one or two inning guy in the pen as he isn't a high leverage reliever like a set-up guy or closer. I know that you would want to keep JZimm here for a long time, but as others have said, after the Gio deal and after calling up Harper, Lombo, and Moore, the farm system is a little light. In order to build a true "dynasty" that I think many want, you need to sometimes let a really good guy go in order to refill parts of the system. Yes, this team has the ability to contend for years, but looking at the facts, you will need lots of free cash to sign guys like Strasburg and/or Harper long term. Those will be potential 30 Mil a season contracts, add in guys like Zimm and Werth for the last years of their respective contracts, try to hold onto guys like Desmond and now you end up with a payroll that escalates quickly. JZimm at his current going rate is going to be looking like an 18-20 mil a year guy when you start adjusting for inflation as well. As much of a blow as it would be, he could be traded for prospects to restock the system and by 2014 or so, you may have the ability to bring up Meyer as a starter. Purke and Solis if they are healthy and develop could be up there as well (moreso with Solis).
Just saying there are lots of ways to look at this in the future, and as much as I think we all want to sign up all the young guys, it may make more sense to let one of these guys go in order to be productive for many many years.
