There isn't one per se, but wouldn't go over $300k on it unless you have CAFS or some huge rescue-pumper need so it's got a bigger body, generator, etc on it. Obviously the less you ask for the better your chances so if $275k will still let you buy something functional then that's better than $300k.
A question related to the last two posts. This is assuming you get by the computer pre-scoring and get to peer review. If you ask for more than the max allowed for a specific item, will you get turned down completely or just offered what that max allowed is? Also, does the answer to this questions chance depending on what program area the item falls under (i.e. equipment, training, vehicle, etc.)
Pricing is secondary to need in Peer, so if you make it and deemed awardable DHS will reduce the pricing at Tech Review. If you're ridiculously high compared to the limit, like asking for $7500 per SCBA when their limit has been $5500, you risk not beating the computer.
Does not change based on category, so if you ask for a $450k pumper with stats similar to someone that asks for a $300k pumper, you'll get kicked to the curb also.