As others have said, buy stuff from ebay as and when you need it and you'll save some money.
Headset wise, buy a second hand BoseX for £350 or get a set of David Clarks converted to ANR by the guy in Hertfordshire. A cheapo second hand DC set costs £40 and the conversion replaces everything but the headband and cups. It works very well and the conversion costs £160. This is what I use. (plus ear plugs).
I suffer from constant tinnitus as a result of using cheap headsets when training and not protecting my ears properly. I know it will shorten my lifespan due to a lifetime of poor sleep and prescription drugs to get me to sleep. The only reason I still fly is because the ANR headset combined with ear plugs has prevented further deterioration.
I've seen studies that showed every GA pilot suffers hearing damage, but you won't know how susceptible you are until after the damage is done. There is no cure, nor is there ever likely to be, so protect yourself properly or you may live to regret it.