Could anyone tell me how to find a gym with reasonable prices?

Yellow pages, Angie's List, Yelp. You'll probably have to listen to a lot of sales pitches, but remember you don't have to say yes.

Edited to add: The local Golden Gloves Association might be your best bet.

Start calling them, ask about specials, if you decide on two or three, go visit them, see what you get for money, Also see if there is any special deals available.

Also, see if everything you see, is included or there are extra charges.

Also often you get what you pay for. Experience of trainers, how many trainers.
How many rings, in my old hometown, there was one, with one ring, most sparring happened just on floor around bag area with little supervision.