1979 Colt Python 2 1/2" blued with factory ivory grips.
Check Gun Broker and Guns International. I'm guessing this revolver should go out at $2,500.00 +++.
If you are going to do the Internet auction thing. Take lots of detailed photos, and have a good write up to go along with the photos. If you can't take high quality photos yourself, get someone who can even if you have to pay for the photos you will recoup the cost with the increase in the selling price.
Good Luck
P.s. I just checked Guns International and found four Pythons advertised, all are 4" guns. Prices are as follows: $2,750.00, $2250.00, $2499.00, and $3,199.00
Generally 2 1/2" Pythons go for MORE than the 4" versions.