I am willing to sell individual domains, yes.
The type of person that will buy 500 domains at one time is a professional domain investor. I agree, most people would have no interest in managing that many domains or bearing the renewal costs of approximately $5000 per year. But when treated as a full-time business, $5000 per year isn't so intimidating.
These domains are not all up for renewal at the same time. You can find a searchable database of all of them, including expiration/renewal dates, here:
http://www.btcdoms.com/portfolio/portfolio.phpIndividual offers are welcome, don't be shy.