The value of like-new restoration paint, imho, only adds maybe $100-$200 to the value of most bikes. Of course, the labor and decals and paint normally cost twice that amount, at a minimum.
However, if you can ride the bike 1000 miles, then that $500 paint job becomes $0.30 per mile (assuming $200 residual value after 1000 miles.) If you can ride it 4,000 miles, then the $500 paint job is $0.08 per mile, assuming you keep it clean and nice.
And you have to make allowance of $5 for each person that walks up and compliments your bike and/or strikes up a conversation. Moreover, every time you pass a carbon bike on a steep upgrade with your vintage steed, outclassing him in both performance AND style, it's obviously worth $12, imho.
So, if you can show it off enough, and ride it enough, pass enough carbon weenies, and meet enough people, a restoration is always profitable, imho ... :-) :-)
- Don Gillies
San Diego, CA, USA