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.
Two channels is a better value than multichannel.
Floor standing full range speakers are a better value than lil fellas on stands.
Read the specs. Distortion specs for an amp tell you if the designer was paying attention.
I don’t really think integrated amps or receivers are a better value than separates. Over a long period of time you’ll accumulate various electronics and you’ll have a favorite preamp and a favorite power amp. It’ll be simpler if your favorites can be matched up without having to explain to family why there are two volume knobs and only one works! and you can sell all the hardware you don’t end up using.
Wear ear protection when working with power tools etc.
You don’t need fancy cables. Plain copper wire for speakers, simple shielded RCA for interconnect, any damn thing for AC power.