Three products that require upfront investment, but long term will save more money than cheaper alternatives.

1. Vitamix
2. Dyson vacuum cleaner
3. Tesla

What are examples of other such products?

Unlearning. Full time product manager. Part time builder/tinkerer on farcaster. Bots: @nftsoffc.

Good quality tools for any task you routinely do (eg screwdrivers, pliers, multimeter).

Toyota to Lexus range firearms (Sig, Glock, DD) vs Fiat or Ferrari 

For me, decent luggage (Vertx, Pelican, Eagle Creek, Rimowa)