The only Colt Commando I could find in my old Modern Gun values book is said to have been brought out in 1984 and discontinued in 1987.
HOWEVER, it is said to have the same specs as the Detective Special, which has been aroud in one form or another since 1926 and was dropped in 1972.....Then a Re-vamp of the old Detective Special came out in 1972 with a heavier barrel and other "improvements"
If your gun is a "Detective Special" and was produced before 1972, and is in excellent condition....its value, as predicted in my Modern Gun values of 1991, is listed at 300 - 325

So with inflation maybe 375 - 475 if in excellent condition....probably considerably less