The Goo Goo Dolls did a club tour last spring and it barely sold out in most markets. I'm not saying either band is bad (I enjoy both) but I've worked in the ticket industry for the last decade and can pretty confidently say that if this tour is priced the way I think it will be priced (ie: too high), I don't see these shows selling out across the board.
I could be wrong. I've been wrong before, but something a little smaller might be more comfortable.
Then again, MB20 had that big radio hit last year that was catchy, so who the fuck knows. Audiences for 90's bands are always unpredictable.
I think the MB20 club tour did really well so, packaged together, shouldn't be bad. Question for you since you work in the ticketing agencies. Can the sheds still do like 6-7k a show and break even? Most acts that play there, it seems they can't fill up the 18-20k spaces.