Možná pomůže modifikace: http://www.gamefaqs.com/boards/540331-stalker-shad ow-of-chernobyl/52804020
If you don't mind playing a modded game, I've included a teleport system. By pressing ESC+J you can choose a point on the level to jump to, including traders.
Mod requires restarting the game though:
http://www.moddb.com/mods/stalker-complete-2009