Just wait and buy them on ebay or stubhub. Tickets for Opening Day 2005 weren't astronomical. I know, I would have sold mine if they were.
People are going to charge an arm and a leg now hoping to get the random sucker who wants to buy one. As the date gets closer and the tickets dont sell, the price will come down.
Even if you have to buy a 10 dollar ticket for like 25 bucks, really what is the big deal? Especially after ticketmaster charges you 8 dollars in fees. If Opening Day means that much to you, I'm sure you could spare 25 bucks. It might be the last row, but whatever, it's a baseball game. Once you are out of the lower deck between the dugouts or bases and maybe very first few rows of the upper deck its all the same.
Everything evens out. There is no magical way to charge and receive ridiculous amounts of money for baseball tickets in at best an average baseball town. Also it is a late Sunday night start, might be cold. If it was a nice day game, you get people who would leave worrk, etc.
I'm really not that hung up on it. Might passively look for tickets or try get something off a scalper close to gametime. Maybe because I went in 2005, I'm not as excited about a new stadium as I was a new team.
A nice september game with playoff implications is what'll get me jazzed