I have a makeup brush habit and have been collecting them for more than 20 years!
You definitely don’t need to spend all that money for good brushes. The Mac and Bobbi Brown etc are nice, but there are much less expensive ones that more than do the job.
I got a great set by BH cosmetics from TK max the other day. It’s called the sculpt and blend set, it’s still on their website for £14.99. Really nice brushes even for the price. It has pretty much everything you need except a good powder brush,.
I do like some of the Real Techniques ones, but they wouldn’t be my go to for everything. I have a tonne of their brushes and only two are in my usual rotation.
My current favourites are mostly from the BH cosmetics set (I’d buy more from them, amazing value, also at Beauty Bay), Kiko Milano (amazing quality but a bit more £), Nyx (a bit £ per brush). I also have nice ones from B at Superdrug. All these have washed well too.
I’d steer well clear of ELF brushes, they’re pretty cheap to buy but cheap in quality and fall apart quickly after washing. Having said that, one of my favourite brushes is by them but I have had to keep buying new ones! I do like the Ecotools brushes aswell although some have fallen apart after washing.
I’d steer clear of those big, cheap sets on eBay and Amazon. Also, get synthetic not animal hair has they’re much easier to look after and I think they’re nicer overall.
For a starter kit, I would look for a decent set like the BH cosmetics one I mentioned. Then experiment with which brush you want to use for which step. It’s personal preference really.
Incidentally the brushes I have had for the longest are some I bought from the Body Shop around 1996. They have the Colourings brand on them! I keep them as a Collection Item now, but they’re still going strong. Can’t vouch for the quality of their brushes now though.