the keltecs are fairly cheap guns
the one you have is a 9-3at
in excellent condition its only worth about 225.00
as far as the taurus 357 goes theres a few diffirent models all roughly worth 250 to 300.
i say its a good trade
mainly because the taurus sounds like it's in better condition.
also the taurus would be easier to turn around and sell.
why does your friend want a kel-tec?
a split second of man made perfection dialogue, speed, and direction.