not sure how much long the pay per listing will be in yahoo now that they have bought out inktomi ...
roxle, take your traffic budget and spend it at inktomi ... you'll actually get signups
being listed in yahoo is about as valuable as being listed on dmoz ... it can help you build other traffic sources if you know how to work them in together.
i have 3 sites listed in yahoo, each gets on average of 1500 hits per month from the categories they are in ... $50 per month for 1500 hits per month is good value if you can make it so ;-)
i have ppc traffic for sale, contact me if you are interested
cj@purve.com or icq 3422430