If it were me... I probably would not buy it, even if the $50k for tools was right. Starting a bike shop is EASY, and the "good will" or "established customer base" in that particular market is very fickle. Typically, bike folks tend to deal with the people they like and once word gets out that hte original owner has sold out, all of that "established customer base" goes away. In my view, it's not worth anything.
Also..... when purchasing an established business, you are also buying the BAD WILL from all of the customers that the previous owner may have screwed through the years. PLUS when you buy an existing shop's inventory you typically get all of the left-over stuff that nobody wanted to buy, like last year's model, or the odd colors. The real value of all that is dubious, at best.
Instead, I'd use that $50k, and what you were going to spend on his inventory, to establish my own shop. Rents and so forth will be the same whether you buy and existing business or not...... and that $50k will go a long way towards advertising. THEN you can start fresh, and do it right..... right from the very beginning.