According to http://marketshare.hitslink.com/search-engine-market-share.aspx?qprid=5 Yahoo has less than 8% market share and Google has 83%. So from a bang-for-the buck pespective, I am not sure that $299 pr year has value as Yahoo does not have enough market reach?
I had seen something on if you add your listing to the Yahoo Canada directory(or other non US Yahoo) there is an option of paying the $299 or the free method which Yahoo may or may not accept your site listing in the directory. Hope that helps.
Guys, no you don't have to pay the money- take some time to understand the market share. I have one new client who had great position in Yahoo but nothing in Google. There is little point in being a big fish in a small sea. It's your money - but I would advocate that you fully understand the market share of the search engines, the share trends of each search engine and your competitive landscape before your invest. regards, George.