If you have never heard of lab128, it’s worth checking out:

http://fwww.lab128.com/lab128_screens.html

lab128 is one of the few tools on the market to harness ASH data. The tool spectrum as I see it is

OEM 10g/11g – $10,000 up to millions of dollars !  ($5000 per CPU AFAIK ) , slow, big install but has ADDM and AWR history

DB Optimizer –  $1500 easy, fast, about and comes with SQL tuning

Lab128 – about $500

ASHMON – free, limited functionality and you have to set up S-ASH collection if you want to avoid the Diagnostics Pack license

There is also Confio’s Ignite, Precise I3/Indepth and Quest’s Performance Analyzer pluggin to Foglight. AFAIK all of these require agents where as ASHMON,Lab128 and DB Optimizer are agentless, and Ignite, I3 and Perf Anal all cost in the same price range AFAIK as Oracle OEM so why not just get OEM if you have that kind of money.