Dwarf magnolia leaves are really nice, especially for a smaller viv. I'll post some photos later but the pricing is a little higher since I hand select all my leaves. It takes a lot more time to hand select 10 gallons of dwarf mag leaves then standard leaves, a lot more time actually.
Anyway, I can do the dwarf leaves for the following prices plus shipping:
~10 gallons - $28
~15 gallons - $40
~20 gallons - $52
Frankly, since leaves are so light, shipping 20 gallons might only cost $1 or $2 more than shipping 10 gallons, so your price per volume goes down the more you buy - but only to a point. Boxes larger than 3 cf (22.5 gallons) are charged based on dimension by UPS, which doubles to triples the price, so I stick to the smaller boxes.
I say approximate because I'm selling them in bulk and my boxes aren't exactly sized for those volumes, but if anything you will get more and these volumes are the minimum provided. I convert box size to gallons by multiplying the dimensions in inches LxWxH and dividing by 1,728 (cubic inches in a cubic foot) giving the volume in cubic feet. Then I convert cubic feet to gallons by multiplying by 7.48 (gallons per cubic foot).