Robinsons do the best Tendulkar shape IMO and have a Butterfly grade. Just make sure it's a good weight, ie. 2.11+ so you get good volume in it. Butterfly tends to be a bit heavier due to the added density of the stain. In terms of performance for price, they can perform very well indeed, but some can be absolute planks. Given the pricing, your best bet normally is to look through shops if you can and find a low graded stock bat. I think maybe about 10 years ago, it was pretty common to get a Butterfly grade bat for around the £125 mark, but with costs going up etc, £200-£250 is a pretty standard starting price point for a custom Butterfly these days. It's not extortionate, but not quite as cheap and cheerful as they once were.
Purely from my own experience, you don't want too heavy a stain or tiger bar above the sweetspot - have found this seems to cause detriment to the playability higher up the blade. Right on or below the middle will tend to be yield good results, and the nicest ones I've used have had a stain in the back right where the swell is. Seems just to help strengthen the blade overall. They also tend to last a bit longer generally, probably cause the stain retains a bit more moisture. I wouldn't say superior to standard non-butterfly clefts, but they're certainly not inferior bits of wood.