It's money well spent.
My 2008 Allez was $800 new, and it's probably worth only $300 now, even though I've likely spent 1500 or more on upgrades and parts over the last decade.
Considering the tens of thousands of miles, and the wear and tear it saves on my nicer bike and cars, it's been a solid "investment".
Bikes and most cars are depreciating assets, so making decisions based on their current supposed market value is dumb.