General directories will not send you traffic. Try to find highly directory in your niche with high traffic. I personally wouldn't spent money on web directories. Better buy good quality content and put on your website. That will bring you stable traffic.
I agree , quality - unique content gives more than submission to 1000 directories for 2 dollars per 100 . BTW how is possible to do manual submission for that kind of money .
It depends what you're trying to achieve. If you want traffic - a directory targeted to your niche will more than likely send you the most traffic. If your goal is to improve search engine rankings, a listing in one directory wont help much no matter how good it is. You need to have a strategy that involves getting listed in numerous quality directories - along with other links of course.
You should start with directories in your niche. Then branch out to the better known general directories. Here's a list of best value directories that should help you get started. You can use the search to narrow the list to your specific needs.
To be completely honest, I think website directories are solely for backlinks. You're not going to get a lot of traffic by posting your site on directories.
I agree with you ,Free doesn't mean valuable and good. However I have launched PR1 directory myself uktoplinks.com and I'm offering free submission for limited period of time just to show what people can get .