Greetings Curdog!
Price is somewhat subjective and I would imagine that you are going to get a variety of opinions here. Assuming that the guns in question are the later, all US production and in "brand new" condition, I would say around $1200 for the SAA and a few hundred more for the Omni-Potent due to its collector value.
If you are planning on doing a lot of shooting, I would definitely stick with the SAA. The Omni, while neat looking, feels awkward (at least to me) and does not balance as well in the hand.
CJF