If the pin can be twisted, then there is no need for a new caliper as the pin can be removed. Even if the pin is severly pitted from corrosion, just replaceing the pin is enough.
I had a similar situation in in-laws Jetta about 3-4 years ago, I cleaned everything up, gave plenty of lube and re-assembled. This year the rear pads needed changing again and all the pins except one (on the drivers side) were moving smoothly. The one that was stuck had a torn rubber dust boot, all others were fine.
To help in pin removal try twisting and pulling on the caliper at the sme time, it will slowly come out.