I've sold the odd bit of kit on, but nothing serious. I think there is a market for the cheaper end items and some of the stuff on this site is very good value, so possibly a margin might exist with the right contacts and prices.Think of it as a pyramid, if you have a £200 bat with a high margin in terms of £'s, the market for that bat would be a select few. If you sell a bat for £50 with a low margin, then the number of potential buyers is alot more. It's hitting a point where prices and volume of customers allow you to sustain a business.
If I was doing it, I'd buy small amounts of stock, few bats etc and gradually build a reputation by going directly to the clubs - either through contacts or doing a few open evenings at the clubs in question. I think alot of players don't have the time after work or a rushed saturday morning to visit a sports shop, so bringing your stock to the club may prove a winner and will also get your face known. Sell your stuff and gradually expand. It may take 2-3 years before going full time, but you'd have a sound base to build on and the contacts.
Having a website is pretty much compulsory, but it doesn't have to sell stock. I worked for a major travel company in the 1990's and our website was doing £1m of business a year simply from brochure requests. You can do the same, or take email orders you can't fulfil in person (or where you have to order stock in).