If you are in trouble of finding your copy of SWAT 4 and you want to buy one instead of some illegal ways to get it, I kindly inform you this one as a digital copy of the game, for example here:
GOG - SWAT 4 GOLD EDITION (standard + The Stetchkov Syndicate for only
40,89 PLN which is around
9.87 EUR (as Google says).
Regards,
KeeRIeS