It just depends on what size of fish your looking for, its allot like hunting!
If you want something in that 8-12 lb range its hard to beat Erie.
10-13.5 lbs Winnipeg, its probably at its peek right now.
11-16 lbs Tobin in the fall. "not as good as it once was and you'll never be able to take a trophy fish home because of the slot length its just to long at at 33.85 inches. Those fish up there are fat.
13-17+ lbs the Columbia " again its nothing like it was 10 years ago but you always have that chance of popping a fish 14+ like the 20.34 lber pictured above caught last spring out of the same pool we were fishing that week. Its a long trip and if one guy in our group takes home a trophy we are heading home happy.
I asked a local fishing legend out there who was from ND originally how his day was one evening at the ramp. He said they'd only caught a couple dinks. I asked him what a "dink" was to him and he and his buddy calmly looked at each other and said. "oh I suppose anything under 11 pounds" right then I knew I was in the right place!
And as far as prices of trips I'd say the average trip costs a person about 550-750.
I've been lucky, since I'm a photographer allot of my trips have been about free because I sell my photos to Infisherman.