There is a place on London road, a few shops down from the Sainsbury on the corner, which I'm sure sells a banana split, if you're still looking for one!
I think eBay's 10% is too high, although if anyone sells handmade items, Etsy is similar to ebay with slightly less seller fees.
---------- Post added 02-08-2017 at 17:24 ----------
Does anyone have any alternatives to ebay and etsy for seliing?