Would you recommend that? Do the lower levels usually have an outfield camera, or just a homeplate camera?
Camera angles are not great for the lower levels, most of the time they are from the press box area so high up. Until last year, the Nats organizations rarely had the video feeds for their home stadiums, but now Hagerstown, Harrisburg, and Syracuse all have it. Definitely better for watching hitters than pitchers.
If you listen to a lot of games like me, then the 40$/year is worth it just for the visual to go along with the game (I believe it is a cheap add-on if you have mlb.tv). Though, if you don't listen/watch a ton of minors games then the camera angles and video quality may irk you or make you feel like it isn't worth it.