i've never missed anything rare, expensive or boutique - just irritating stuff. a 'broken on the first ride' x-9 mech with perfectly good jockeys went for £3.50 POSTED!!! they would have been pretty cheap & handy spares. a bar & stem combo I really wanted that would have matched the seatpost on a build perfectly (same brand & model) went for £2.50! an lx wheelset I was eyeing up on a really bad listing went for about £12 and only about 8 miles away from home too. there are a couple of others but nothing important or critical to a build.