I suppose that's what a credit card is... emulated money.
Amiga, like all computers though, will be far more enjoyable if you can interface with the real world.
If you enjoy writing or graphics maybe adding a printer to one of your Amigas would be a satisfying investment, as would a video digitiser, scanner or sampler for getting things into the machine.
A network adaptor like an ethernet card would help you share files between Amiga-Amiga or Amiga-PC.
Make sure at least one of your Amigas has a CD-ROM for gulping in masses of programs and media.