The previous poster was right. Amazon has had the entire 7 seasons of VOY as a complete series package for around $220.
I think I remember ENT entire 4 seasons complete series for $157.
The way to save the most is to buy the entire series and only from an online major vendor.
I am confident that ENT will be on Blu-ray next within 2 years and will wait. I've only watched about 10 episodes of ENT via Netflix and am getting into the show and know it will get better looking on Blu-ray and with more special features.
As far as the I-XI Trek movies only STII:TWOK had a proper restoration and was "properly" mastered to HD for Blu-ray. The 2009 XI film has a immaculate transfer too. The rest all have issues with their HD telecine transfers and subsequent digital processing before the video encoding and it has been mentioned in the reviews. You can expect Paramount to rerelease the Trek films on Blu-ray within 5-6 years. At that time we'll probably see the director's cut of ST:TMP on Blu-ray for the first time..