You know, the small things that can save you a lot of money. I’ll start:
You can get “hospital” powercables that are completely shielded for 20 bucks or so.
You can get anti vibration pucks for washing machines instead of spending 10 times that on the same product which is just labeled as “speaker pucks” instead.
May be frowned upon among audiophiles and not be for everyone, but for me (YMMV) 80 bucks for a used “aural exciter” improved the sound significantly.
Other than that, I often buy used, and almost as often even make a profit if I sell the gear again when I upgrade.