When I got into this, I started where a lot of guys did - with a pair of TF10's and a pair of IE8's - so I had a decent BA headphone and a decent dynamic one - they were heard and shoulders better than anything I had listened to before that point. I had an extensive background in mobile audio, so I know what sounds good and I knew what kind of signature I liked (when I would set up a high end car system, I found myself preferring sealed enclosures and woofers no larger than 10 inches - I liked the bass to hit me hard, not ooze all over my body like ported 12's and 15's did.
Since then I have played the game of $50-$100-$200 FOTM phones and am actually happy that I made the jump to high end CIEMs - What the myriad of middle ground phones has done for me is make it so that my throw away phones (Gym, running, or the ones I have given as gifts) tend to punch way over their price point. But for my listening pleasure, I want the best I can afford - if I make the wrong choice, I can sell and try again - but I am happy with what I have - and upgrade-itus isn't hammering away at me - maybe I'll buy something better down the road - but when I listen to music I am listening to music, not thinking about what another expensive set of cans would sound like.
Buying headphones is like buying cars, homes and musical equipment - buy the best you can afford - buy quality - and start enjoying life as soon as you can.