fatpeter - 9:40 am on Dec 20, 2009 (gmt 0)

"What kind of search traffic could I expect if I were able to fight my way up to position #3, #2 or #1?"

From my experience 50 visitors in 4th place would roughly translate to 500 visitors for first place. That experiment was done over a period of a month with 2 sites of mine which seemed to have rock solid positions at the time. The only difference was the first position had sitelinks at the time so your mileage may vary