I just created new playlists myself but iirc there’s a bunch of software to do it online

I used Spotify for years before moving to Apple Music about 6 months ago (due to a student discount). Honestly, I quite like it. The biggest criticism people seem to have when they move away from Spotify is that other apps have inferior UIs but after a couple of weeks you get used to the AM UI so don't worry about that. Music quality is great and I find the discovery/auto play features to be pretty good (can't compare to much to Spotify though as I never really used them that much before I left). Be aware that on Windows the AM Preview is only available from the Windows 11 store in the States (unless you VPN and change location in Windows settings) although you can use the Windows Subsystem for Android to install the Android app on your PC which actually works pretty well. Alternatively you will need to install something like Cider which doesn't support AM's lossless options.

I'm guessing you're going to be hard pressed to find something cheaper than the B2s which have better detail, but you'll certainly be able to find cheaper IEMs with different tunings which you may prefer overall :)

I got the s12 a couple of days ago and have owned the ie300 for a few months. I am no expert so maybe you wanna take my opinions with a pinch of salt! I really like the ie300s for their comfort more than anything else, you can easily wear them all day and forget you have them in. In terms of the sound, the ie300 has more bass than the s12 which has a lot more treble to my ears and I find I need to listen at a lower volume. One thing I will say about the s12 compared to the ie300 is that the sound is much wider, whereas the ie300 sounds very close. Vocals are so much clearer on the s12 if you care about that. If you're looking to get a cheaper IEM with more bass I really enjoy the Truthear Zero and out of the three IEMs I mention I find their bass to be the most enjoyable (really good punch, when I listened to Karma Police with them for the first time it put a genuine smile on my face!).

I had a similar problem with the stock Sennheiser tips on my IE300. I got some Spinfits and don't have the issue anymore so maybe it is worth trying some different tips, perhaps foam?

I just looked and it now says the total is $195. I’ve looked a few times over the past couple of weeks and it was the 135 with the DT02 dac. Perhaps it was a pricing error which has now been corrected.

I have been thinking about getting them myself. On the website it looks like you can get their DAC too, for the same price as just the IEMs?