Do have any bang-for-your-buck kind of modules that you'd recommend?

go for doepfer - matrix mixer, sequential switch, polarizer etc etc

joranalogue compare 2 is an interesting logic module

"some of the best base-level info to remember can be found in Jim's sigfile" @Lugia

Utility modules are the dull polish that makes the shiny modules actually shine!!!

sound sources < sound modifiers < modulation sources < utilities