I know the dealer stung me for $320 for a leakdown test after my compression test results were bad. They also broke the remaining OK coil connectors...
you can't do any worse than that by buying a 20-30 dollar compression tester and spending an hour or so doing it :)
Good luck
Chris
95 TT red (daily driver) 01 BMW 330xi black (winter beater) * lost in divorce :( *