The HxC slim is now only
£49 delivered.
It will effectively give you ever single floppy disk ever on one SDHC card. You won't need anything else. No memory upgrades, no hard drive. You'll be able to play the entire Amiga game back catalogue and 68000 demos.
But....
For £48 (plus whatever you can get for selling your A500) could you buy an A1200 with a CF card hard drive and a WHDload license?
You'd get one or two AGA games you wouldn't otherwise be able to play, workbench would be slightly faster with a 68020 CPU, loading from hard drive would be faster...
It is borderline...