Why don't you get some local painting contractors out to get some quotes? Asking people here not familiar with your actual build nor the costs in your area is a complete crap shoot.

Yep, we're definitely trying to do that too! So far, a couple of contractors have said they don't even want to give us a price range until they see the porch...but it's not built yet. But in order to build it, we need to budget for the cost of painting/staining...so we'd just like to get a general range of how much it might cost (understanding that it can vary quite a bit).

They may be able to give you a budget number if you have a set of blueprints from an architect. Other than that from our side of the keyboard it is even more impossible than they are telling you.

Yep, we're definitely trying to do that too! So far, a couple of contractors have said they don't even want to give us a price range until they see the porch...but it's not built yet. But in order to build it, we need to budget for the cost of painting/staining...so we'd just like to get a general range of how much it might cost (understanding that it can vary quite a bit).

We're having a screen porch built (15x20 w/ tongue and groove ceiling. It took our carpenter about 2.5 solid days just to stain wood. Maybe that helps if you can figure out hourly rates?

I would really not be comfortable separating out construction and staining though. What if something goes wrong and the stain does not come out right? The stainer could blame the quality of wood used, and the people who did the construction could blame the stainer and you could be left not knowing who to hold accountable.

Seems like a recipe for trouble to me.