So, what to do? It is possible to perform some repair work on the fabric. Campmor, among others, sells Kenyon Recoat 3 ($8 a jar; www.campmor.com), which can be painted onto fabric that's lost its waterproof coating. But the stuff is a little hard to work with, and not as durable as the original coating. Plus, the tent may have suffered other damage by now; in many cases, tent fabric may look just fine but has lost 50 percent or more of its strength due to rot, UV damage, and so on.
If you want to go four-season, then Sierra Designs' Hercules AST ($399) is an extremely good option, if a little hefty at about nine pounds. Likewise, Mountain Hardwear's Trango 2 ($450; www.mountainhardwear.com) is another nine-pounder, though it does mix in a roomy 40 square feet of floor space.
In short, I'd go for either the Orion or the Hercules. Tell your friend to foot part of the bill. And don't loan him a tent ever again.