^
You're missing...
Lockring: $10-20
Bar tape: $3-15.
Stem: $20-70+
Bottom Bracket: $25-100+
Headset: $30-60+
I guess we could throw in two rolls of Velox tape for about $3.
Also, handlebars are probably going to be $20-50.

The point is, it is not going to be done easily with only $500.