I did a private 1 day Mekong Delta tour with Lose The Tie tours. Vi the owner provides an excellent service. I can't remember the cost but my guide Rose and I had private aircon car (with driver) from my hotel and then private boat etc for the tour. All very efficient and I'm very glad I made the choice to go private rather than join a group tour.

I actually used Lose The Tie tours for a couple of tours in Saigon and they customised them to my needs. I was really happy with everything. Prices varied depending on the tour and "type" of guide (i.e. if you're looking for a very official style guide or just want more of a companion/interpreter).

I will definitely use them again!

http://www.losethetietour.com/