to do a quality retro job on what they aer selling would cost much more.
3x250w HQI......for 3 IC MH ballasts and 3 pendents you are looking at $600 + Bulbs then add a IC 660 for the VHO's and your $150 + bulbs.
then how are you going to mount them? $$$ its $1,000 + to do a high end retro. Depending on the quality of the hood you are looking at $800 could be a good deal. if its junk, spend the extra cash and get the best retor you can.
If you dont need to go HQI, then you could do the retro for less.