Postage cost for pocketfold invites??

So I am thinking about invites alot lately...wondering which style pocketfold is more expensive to mail out...
Are the pocketfolds with the pockets on the bottom more expensive to mail then the pocketfolds with the pockets on the right or left side? Also do you think a layered card instead of a pocketfold would be cheaper?
TIA
Edited spelling...again...lol