As an Engineer in charge of product development and process improvement, I always had to do the calculations to validate my projects. I was given a budget and had to stay within the lines. Over and I got no raise that year. A lot under and they had to shortchange my coworkers so they could pay me extra.
In 2005 I bought an antique fixereupper. I tracked every single expenditure, as well as hours worked. (I did not add labor to the cost; I just thought it was neat to do.)
At the end my totals were about 5 grand. A professional appraisal indicated the boat was worth about 10 grand. Four boat shows later and with 2 first place trophies and a "best in show" I figured it was worth more than the appraisal.
Now, 20 years later I see similar boats selling for 5 grand. The bottom has fallen out of the antique boat market. Boats advertise for more, but they don't sell.
Moral of the story is that times change.