Yes, Melanie....if you put 5 oz for 1 bar and someone buys 2 it will calculate at the 10 oz rate.......3 at the 15 oz rate (1st class if you have Etsy label prices selected and Priority if you have retail rates selected.
If someone gets 4 bars, the calculator will automatically figure for Priority shipping since the weight will be over 1 lb.
Or if you have both Priority and Parcel Select both in your shipping profile, I think both of these will show up to the buyer.
Is this 5 oz. including your package/mailer or is it just the bar of soap?
If not you need to factor in the weight of the mailer also because when you mail it you're going to put in the total weight..
