working in the computer field all my life, there was a decade or two when equipment like modems and external drives had a usable life of only a few years. during this time when equipment was tossed, i routinely threw the AC adapter into a draw that today still contains dozens of small modular power supplies comprising many different voltages and current capacities. when i hit upon a good operating voltage for an accessory off a standard variable transformer, i can usually find a comparable or close enough fixed modular supply to act as a dedicated supply.
alternately here in town we have two very large electronic surplus stores and if i ever need an oddball supply, i can usually pick something up for a buck or two.
cheers...gary