Complete series set on BD for Enterprise, coming on 04/01/14 (it is a Tuesday, so it's a legit release date):
Found it on Blu-Ray.com:
$307.99 at the moment, retails for $439.99.
Might not be worth it since the single season sets have been less than $77/season by no small amount. I doubt it'll release for that price, though unless it gets down to $200 or so by release date, it likely won't be worth picking up.
S1 lowest price to date: $35.34 (Amazon)
S2 lowest price to date: $52.34 (Amazon)
S3 releases on 01/07/14
S4 releases on 04/01/14