What are your options for expansion (either of that facility, or in the area)? Realistically at this point, if you wish to build a program with higher levels, you will need a pit, etc. So I would consider that.
As far as a reasonable price, that seems like it would depend on the area and the business to a great extent. I would try to crunch the numbers (total revenue minus total cost) and then consider the asking price. I'm not a business person (as you may tell by the above ratio, I think they would call that a "profit loss statement" on the business/accounting end

- we deal with marginal costs in economics), but to my mind liquidity should always be a concern. Presumably you'd be taking out a loan, so I'd look at how much you could put down versus that and make sure you're not going to be overwhelmed every month. Also obviously there's been something of a credit crunch so you'd have to look at whether you can get the loan you need.
Also, you didn't mention the details of this, but I've been at gyms where the building was leased. I don't know how common this is geographically or whatever. But obviously in that case I would take care...I have seen a gym after 20 years of business in the community lose their lease...never late on payments or anything, another bigger business in the area wanted the space and was willing to do what it took at the time. Of course this business has since gone out of business

if there is any potential for this, I'm inclined to say in these times especially, are there other facilities you could potentially move to in the area, etc.