How much rebate is appropriate for photography sales?

Rebates for selling this equipment can be referred to the following:

Photography sales rebates are generally based on the sales volume of a certain model reaching a certain level. For example, when the sales reaches 10 units, 2% will be returned (a certain price, such as the purchase price), and when the sales reaches 50 units, 4% will be returned, etc.

Restrict dealers to only purchase goods from fixed channels (there are no rebates for goods purchased from non-fixed channels, or because the purchases are scattered, even if the sales volume is large, the amount of rebates will be affected because they have not reached a certain level), This prevents cross-selling and parallel-imported cameras from other specific markets.