I bought this new betta from my nearest Maidenhead Aquatics. They keep them in one of those units where each fish has a small tank to itself, and the tanks are in rows where the water trickles into the top row, overflows into the 2nd row and so on down to the bottom, then I assume through a filter before being pumped back to the top row. They also have different bettas - I can't remember seeing a veiltail there, the bettas are either crowntails, superdeltas or half moons with the odd king betta (extra large palakats). I've even seen very expensive koi bettas there. Yesterday they were obviously awaiting a new delivery as they had only half a dozen bettas. They were mainly crowntails (which i don't like, but that's just me) and a couple of marble pattern which I know can change colour. There was one reserved fish that would have been very tempting - mid blue body with dark red fins. But the fish that stood out for me was the one I bought, and he was perky and flared at my finger which is always a good sign.
The new betta is the 4th I've bought from this branch of MA which hasn't been open as long as the others within driving distance. The blue marble delta tail which turned plain blue was the first, he lived 23 months; then the plain peach half moon which lived 291/2 months; then the 'neurotic' peach and pale blue which died in April 7 months after I got him; and my new pale blue and red betta.
However, the MA that burned down in the garden centre recently (my second nearest) kept bettas in tanks with other fish and they were virtually all red or dark blue veiltails.
For those of you wanting to buy a betta, I recommend looking at all the MAs you can get to. They do vary a lot in the bettas they stock. And the better ones do stock an amazing assortment of bettas.