My findings that an average $200 spotting scope is more than just perfect for FITA, but I would not go below 100, I have seen and the glass quality can really make difference...
I would like to call your attention to a good tripod, this not necessary to be 200 bucks expensive, go and find a most stability possible where you can extend the legs and extend the neck and tilt the head....not much room there on the shooting line so need to manage the available space as much possible.
Years ago I got one amvona AT-858 (dynatran) from ebay, skeptical at the first but when arrived it was my real surprise how well and strong was built. All aluminum and casting no plastic parts, heavy duty looking and behaving, the pro photographers may never vote for it but for a ~70 bucks finding this as a best bet.
Need a good leg room also a safety room for the bow-riser
I have two spotting scopes and my vote is going towards my birding scope (Eagle Optics Denali 15-45x60 regular price 269 but on sale now for 99
http://northmetro.wbu.com/content/show/28689) also just for an every day shooting or walking around have a Vortex monolucar....