The only time I have ever seen an $100 bill was if I had to cash in more than $100 at a Vegas cascino and I saw very few. I go with my girlfriend and she loves to gamble. I don't, so my limit is $100 a day--and sometimes I don't even spend that on the slot machines. We have a time-share week that we use there.
I live less than 10 blocks from a Federal Reserve Bank - I doubt they give out samples, although, I'd love to have several of these - perhaps a nice stack of about a foot high....