Amazon has Star Trek: Original Motion Picture Collection (Blu-Ray) on sale listed below.
Star Trek: Original Motion Picture Collection (Blu-Ray) $34.99 with free shipping
Includes
Star Trek I : The Original Motion Picture
Star Trek II :The Wrath of Khan
Star Trek III : The Search for Spock
Star Trek IV : The Voyage Home
Star Trek V :The Final Frontier
Star Trek VI : The Undiscovered Country
The Captains' Summit Bonus Disc