My league just started auctioning this year, so I can't help you with the data, but I think as a general rule there are some specific strategies that you can apply based on league size.
I think in a 10 team league, there is much more incentive to go stars and scrubs. Go ahead and spend 58 on Ray Rice, 38 on Brees, 35 on Reggie Wayne and 30 on Roddy White. Then fill out your roster with the 49 dollars you have left. Less players will be drafted which means more guys ready to be plucked after their big week 1-4 performances. Guys like Bernard Scott, Leon Washington, Mike Bell, Javon Ringer, and Kareem Huggins are just one injury away from being weekly top 25 starters.
In a 12 team league or deeper, most of the above players are going to be drafted and you're going to be grasping at straws to fill your last few roster positions if you invest too heavily in your top picks. In these formats, I like to devalue stud RBs to the point where I don't spend more than 35ish on any one guy. You can still get 2 or 3 guys of the Ryan Mathews, Beanie Wells, Pierre Thomas, Jamaal Charles ilk and fill out with sub 10 dollar guys like Ahmad Bradshaw, Leon Washington, Donald Brown, Fred Jackson etc. Not investing $50+ in your RB1 should free up some cash to land a top QB and at least one top WR. Maybe Romo for 25ish and Wayne for 35?
There are plenty of 1-5 dollar guys that should at least be startable at the WR position in either case--- Jacoby Jones, Bernard Berrian, Nate Burleson, Legedu Naane, and Jericho Cotchery to name a few.
My league is 12 teams, so I'm gonna try to spread it out. Here's hoping the top guys go for inflated prices.