I spoke to another one of my LFS yesterday and they said they would take any betta off spring in exchange for store credit. They even offered to lend me a load of 2ltr square jars for separation, if I need it.
I asked why they were being very generous and they said that they would be better off taking a local 'breeders' fry, rather than having them flown in and that they would at least know those betta's would be healthier.
I then got into a discussion about a 80ltr tank with a stand that is on sale for £200. They said my store credit could go towards that
So, I am weighing up my options before hand, still on the fence about it though, need a little more time to think it through.