If the frame is 531 throught (inc. fork legs) with nice lugs, then 60 squid is probably OK for the frame alone...depends who made it as well. Not all old frames look great as fixies - I prefer older frames so that when all the gear stuff is stripped, you don't have redundant bits sticking out like shifter bosses.
I agree with the others about 105 - I've got a full 1989 groupset lying in a carrier bag in the garage - can't even be bothered eBaying it...
You'd only be using the brakes and crankset anyhow. 105 BBs are crap so would probably need replacing...
what frame is it then ?
Willi Moore Tourer 531c / Record (~1985) | Dawes Edge XT (1994)
MBK SuperPro (2002) | Dave Hinde Airplane (2003)
Reise Und Muller Birdy (2007) | Cove Stiffee (2009)
Dawes Jackal (1988) - Sold | Kona Explosif (1989) - Stolen
Dawes Stratos (1991) -Sold | GIOS Compact Pro (1993) - Sold
Trek 8500 (2001) - Sold