Back in 2002 I sold a 500 dollar star in CU condition for 1600 dollars. The book value mentioned 3,000 but I couldn't find any takers at all at that level. I think this is really too specialized (like collecting radar numbered notes) for most people. Also it's not as if there's a lack of banknotes to collect. Actually the reason I moved from coins (Mexican 16-19 century crown sized pieces) into casino chips is that it just became too silly (and expensive) - some coins were being quoted at stratospheric prices for the most minute of differences.