My dad was a taper for the Grateful Dead and was even a soundboard guy for awhile, and i will tell you that so many people overpay for audio equipment. You would see these guys who have never taped using $8000 mics and they were dumbfounded when their recordings would come out like shit. My dad mainly uses Sennheiser 421's (the MKII version), but uses other mics depending where the show is, how far away he is, etc.
Anyways, he obviously owned a lot of pairs of headphones since he was a taper and his favorite and my favorite were the Sony MDR-V6's. They made several new versions of that headphone that are good as well and you can find them new for about $150-$160 on eBay or around $100 used. They are a great deal and tons of audio professionals and sound engineers use them. The Howard Stern show has like 6+ pairs and Howard himself still uses them. I've seen many musicians use them as well, so if they are good enough for them then i think they are good enough for me.
Same with speakers. Yes, you can go and spend thousands on them, but you get diminishing returns. I have speakers that cost more (polks, yamahas, JBL's) but for example my 16 year old Sony floorstanders i think sound almost as good and they cost like $200 for the pair.