A fairly accurate scale would probably be a good investment -
The seller has to have an idea of how much something is going to cost to ship - at least have the weight of an individual item.
The shipping costs - and time - add up quickly.
For example - one can get 6 to 7 yards of quilting type cotton in a flat rate envelope - but it takes a fair amount of time to get it folded up small enough to "make it fit" - so there is a trade off in saving $ and spending time.
Nothing like doing a bit of "packing and shipping" to view that whole topic differently!