There's a Bacchetta big bag for my beginner's bike, a Cafe, but it's 80 clams, which seems pretty high.   What sort of low cost bag solutions are you experienced people using?   I'd like some alternatives to consider.  
 
Thanks

You might try http://www.calhouncycle.com/productcart/pc/viewCategories.asp?idCategory=14.  I use the Lone Peak on mine and have plenty of room.  Of course, I use a back rack bag as well.

Thanks all.  
 
In desperation for a Saturday ride, I just went to Target and got a $14 Schwinn bag that with lots of finagling, seems to fit on my Bacchetta seat.   Yeah, it says Schwinn from the backside, but believe me, it looks worse from the front.