Loads Dan loads...
Me too, but mine won't involve money so much as swapping parts between bikes.
I have a small fleet of bicycles, so when one gets an upgrade, the old parts go on down the food chain to upgrade the next bicycle below it and so on.
I have inherited my father's primary touring bicycle, which is identical to my most-favorite randonneur bicycle. I can leave it as-is (same frame size) and it will fit by only raising the seatpost and swapping in a longer-reach stem. This is the sentimental favorite because it would still be configured as he had it, with tandem dummy grips and guidonnet brake levers fitted to randonneur drop handlebars.
However, the bike is fitted with 27in wheel and tires. I have a spare set of 700C wheels in a wider OLN, so the rear dropouts would need to be spread and the dropouts realigned from 126mm to 135. The new wheel's cassette hub would substitute for the present freewheel, and I have a crank to duplicate my most-favored 3x7-sp half-step and granny gearing, so it would ride nicely.
If I swap wheels, their 4mm smaller radius will demand a change of cantilevers (I have them already, and pads) and then likely a change in brake levers...and so it goes. The tires fitted on the new wheels are a bit wider, so the fenders will need swapping (have those too), and so the end result will be much different than it is now. I'm not sure how I would configure the rest of the bike, but it is a fun exercise to daydream about. I won't be able to do anything to it till Spring thanks to cold winter temperatures in the garage and lack of time, so I can ponder and think about what direction to go. It has a BB-mounted dynohub and will likely get the B&M Cyo R that was bumped off the Nomad when I got the Cyo Premium, and so I'll have lighting but no charging capability. Hmm. Maybe just an alu-rod rear rack and rack-pack for a dedicated "faster" machine with rigid seatpost?
Decisions, decisions -- but the fun kind, so no worries and no money involved, just parts-swapping between the steeds.
It can be as fun to revive an old ride as it is to spec a new one.
All the best,
Dan.