Automatically calculate price based on specific units

I've tried searching the forums for a solution but this problem seems unique. I'd appreciate any help you can provide!

I'm selling rolls of labels that can be bought in any quantity over 4. They are priced per 1000s of labels. Each roll has a different number of labels on it. Example:

• Product A has 5,300 labels on a single roll.
• You can buy a minimum of 4 rolls. (So 4 rolls in your cart x 5,300 labels per roll = 21,200 labels).
• The cost is $1 per 1000 labels, so the cart should calculate the price to be $21.20 (21,200 / 1000). Instead, it's obviously calculating the total to be $4 (4 rolls x $1 each).

I've tried different combinations of quantities, minimums and units, but nothing seems to work out correctly. What am I missing?

Thanks!

Price it by the roll $5.30

kobra:

Price it by the roll $5.30 Thanks for your reply. I could do this, but to compare Product A to Product B, pricing it by the 1000 puts all products on an even keel, so you can easily compare which is cheaper...

Zencart can only deal with one quantity aspect, so you would have to price them by the roll and spell out the number of labels on the roll, and the price per 1000, in the product description. I don't know any way to do what you described in your OP.

If you're creating these rolls of labels, another obvious option would be to make the number of labels on a roll all the same.