Depends, which model is it?
Even Colt carbines with short factory 10" barrels don't seem to be selling very well in the EE. What it's worth and what people will pay are two very different things.
For example, a guy has been trying to sell a Colt Defence 9mm with factory short barrel for around $2600. Some people will tell you that that's a fair price, and I won't argue, but it's been sitting there for a couple of months now.
Seems that not too many people like the old fashioned Colt 9mm's compared to the flat top, tricked out with rails and got all the geegaws rifles.