A great listing just showed up on ebay for a Complete NES Game Collection with Nintendo World Championship. A collector could get every single game made for the NES plus quite a few unlicensed games and Nintendo World Championship in one auction.
The starting bid is $999 and there is a reserve (much higher than that) but the seller is throwing in free shipping if you win. This auction will probably sell for more than $10,000. If you add up all the NES game values from our NES Price List page you get $5,600 and that doesn't included NWC.