Again, no sales numbers but these rankings show that even the 5 year old release of TOS season 1 (# 20,191) is currently outselling ENT S1. All I'm saying is that it's very possible that some Paramount UK marketer looking at this chart might think it's a good idea to try something different pricewise.
I hope that fans of the show get all four seasons released. Hell, I may even grab season four. But I figured the show would be a hard sell, even among the die-hards.
I shelled out about $350 dollars when the seasons were released on DVD and I've watched them so little I simply couldn't justify putting out another $250+ dollars to buy them again.
EDIT: They should've released Enterprise
in the gap between TOS and TNG. It really made no sense to release the two series (TNG, ENT) concurrently.