Not necessarily expensive but make life alot better, such as quality snare strainer, snare wires, snare strap/band, hi hat clutches, bass pedal, throne...just quality hardware in general. Luckily, they are more plentiful and affordable than ever.
I've had old Ks but sold them, I think so many are way over-priced at ~$1000 that don't sound great...of course many that do as well. Would love a Spizzchino but at $2000, no way...I like the sounds coming from K Con/Kerope lately which considering the comparative price point, not snobby at all. And sure, I really like boutique like Canopus and N&C which make me a snob but if I look at a Craviotto private reserve, SQ2 or A&F price then I think I'm getting a great value (and I've never bought full price). So many great hi-end snares out there though I could happily live on a cheap Acro.