Promotion That Does Not Affect Payable Amount To Vendor?

We would like to offer a store-wide promotion to our customers but we do not want it to affect the amount payable to our vendors. The payable balance to our vendor should be calculated on the amount before a promotion is applied instead of after. The promotion would be taken from the store administrator's commission instead. Is there a way to accomplish this?


Admin commission = 10%

Promotion = 5% off order

Order value = $100

Promotion value: $100 * (5%) = $5

Amount due to vendor: $100 * (90%) = $90

Commission collected by admin: $100 * (10%-5%) = $5

Anyone figured out how to do this?

possibly create a 5% promotional code to be entered at checkout.

The only way I think would work is to modify the store plan or create a promotion store plan at 5% and move vendors into the plan while the promotion is running.

You then create a 5% discount offer for customers to bring it back to 10% for vendors.

This is still not totally correct as:

$100 sale

less 5% discount = $95 Sale total

vendor receives 95% of $95 = $90.25

You loose $0.25 of your commission giving you 4.75%

Vendor receives 10.25%

I am looking for the same solution here. The store promotion, not only reduce the vendor money, but admin commission.

Can someone help how to change the payout calculation to before discount price.