Space heater? I'd like to keep the temp largely down during the winter to save money while warming up the part of the place I'm in

I fell for this meme but it neglects to account for the fact that furniture & flooring has thermal mass and gets cold as shit when it isn't being heated. It also takes a very very long time to heat up (again because of the thermal mass). Just turning on the heater so the apartment & all its furniture was always a comfortable temp without me wearing a toque & fingerless gloves & slippers & always being covered in blankets & drinking hot water was probably the greatest possible improvement to my happiness & comfort for the money spent.

Rice cooker

Hell yeah, get a nice one like a Zojirushi if possible

Cold brew coffee maker

Loose-leaf tea equipment is very cheap if you're into that and are looking for a more moderate caffeine hit

seltzer water thingy

Airstream is an israeli company btw