I think that the OP ask if directory submissions help more than a keyword rich site. So if this i the question the answer is that if you dont do both you are not going to reach first page of G for a competitive keyword.
I heard u get 1 or 2 clicks on it perday.Those are targeted clicks. Thats about 365 to 730 click peryear, so its up to u to know if that amount is worth it or not.
Why would you pay for entry into Yahoo? Produce a good site, optimize it for Google, then submit your site through the free Yahoo link; it'll do fine! BTW, one of my clients gets a third of their organic search results from a free Yahoo submission than has 1st and 2nd SERPs on their primary keyword.
I think submitting to Yahoo Directory is more or less a status symbol these days. One can use that money and split it among other quality directories and get a better result than submitting to Yahoo Directory.