My budget is fairly small, living on £5 a week, admittedly no responsibilities personally.
So far I've spent about £60 on my A600, got 2 SEGA pads, a Tank Mouse, WB 2.05 disks, PCMCIA-CF and a 256MB CF Card. Then got given a few floppies, and an A500+ with a floppy that doesn't read disks for whatever reason.
I'm reluctant to spend much more, a memory expansion for my A600, a CF HDD for my A600 and an internal floppy for my A500+ will keep me happy for a few months, grab a serial cable so i can play network, even though everyone i know kind of despises old Amiga games, except all of them love Settlers and Lemmings, because they're legendary.
Retro gaming is almost as expensive as modern gaming.