If you can be bothered researching Chinese brands on a forum like Head Fi you will get a lot more for your money than you will from the big known brands Some excellent in ear earphones for very reasonable money. I just have wired ones, after a bit of research I got the KZ ZS10 Pro, it has six drivers per side. Prior to these I have used sets for around £30, with Soundmagic E10's being my favourite. These cost £30, and totally blow them out of the water in every respect. The instrument separation is superb. There's a lot of good ones about. I decided to pay a bit more and I'm waiting for some CCA C16 in ear earphones to arrive (8 drivers per side). These were £69. I was that impressed with the KZ's I decided to pay a bit more. I use with a fairly inexpensive Cyrus Soundkey headphone AMP/DAC. They were very good with an Iphone, but this makes them even better. The body of these IEM's are slightly bigger than most IEM's due to the amount of drivers, but they are not really that big. Single driver ones are available from other companies, the BLON BL-03 are supposed to be very good for a more compact, single driver IEM.
I'm amazed out how good these are for the money. I've never spent a real lot on this kind of thing. I have some Grado SR80e Prestige over ear, open backed headphones that cost about £90, pretty well reviewed. The £30 KZ's sound better them to my ears. As with any in-ear if you don't get a good seal, they'll sound pants.
KZ are a big Chinese IEM manufacturer, CCA is their sister company. They do bluetooth ones too, but I don't know much about them. You'll get much for your money than you will with Apple, Shure, Sennheiser, Soundmagic etc..
Just a thought, if you have time to research on Head Fi or somewhere. You can buy them on Amazon if you want to pay more, I got mine off
Ebay off a UK seller, can get a bit cheaper again from China. They are not that kind of thing that copies made of them, unlike Sennheiser etc.
If your looking for over ear the above doesn't apply. A good set of in ear, with good seals are surprising good..