There are plenty of decent earplugs around for about 10/15 quid. They contain an acoustic filter that attentuates all frequencies by roughly the same level (as opposed to the foam ones which tend to muffle high frequencies).
I used to have a pair of these:
http://www.enhancedlistening.co.uk/product.asp?P_ID=1458&strPageHistory=related
Fuck knows where they went to tho.
In terms of sound I don’t think there is much difference between musicians earplugs like these and expensive fitted ones (the filters used are often identical). The main difference is that fitted earplugs are a lot more comfortable (which means you’ll be more likely to wear them), and for a lot of people this is well worth the extra money (if I had more money and could trust myself with not losing them I’d buy a pair). TBH I found the Elacin plugs uncomfortable and generally couldn’t be arsed with them, although they are far better than foam plugs, and the xmas tree shaped plugs tend to be the best value for money.
It’s actually quite scary when u realise how damaging loud sound systems can be to your ears (one thing they taught us about in my first year at uni was hearing damage, and some of the graphs they showed us were pretty uncomfortable viewing.)
