...after paying $299. I read a few SEO "experts" praise the importance of getting into it, in so far as PR and search ranking in Google go. We'll see what it really does for me.
You either pay $299 to get your site reviewed in 7 days and hopefully get included, or submit for free and pray they consider it within the next 6 months - 1 year. Many SEO "experts" consider it good for Google rankings to be listed in the Y! Dir since Google sites the dir as one of the important places to be listed in its webmaster tips. The homepage of the Y! Dir is a PR9, which can't hurt either.
Congrats on getting listed. Hopefully, your listing isn't going to be buried on a deep page and you'll see a bit of traffic. Andy Hagans at Text Link Ads likes the Yahoo Directory as well.
My 2c here: If your site is an MFA or generating revenue from advertising kind of site it's not worth $300 to get listed 90% of the time. But if the website you're submitting is a business, one that makes sales, then it's absolutely worth $300.
Go to the category you want to submit to, at http://dir.yahoo.com, then click Suggest a Site near the top-right, and choose the Free option.