Buying groups, like fish stores and tax prep places and deals blogs and landscaping services, are businesses. Businesses exist to make $$$. Said profit is generated when the proceeds from customers exceeds cost of goods, labor, and overhead. The lower they buy and the higher they sell, the more profit is made and the better a business it is. We've all seen the results of bad businesses that defaulted on tens of millions of dollars on people's cards. It's obviously in every buyer's best interest that the buying groups be managed by a competent business person who understands market dynamics, supply and demand, and cash flow. If the competition's commission would be higher and the buying group would have their supply source threatened to a degree that the net impact to the bottom line would be negative, they would probably give higher commissions, given that we are operating under the supposition that they are run by competent management. Being as the commission is what it is, presumably this is what market conditions dictated prudent for them. C'est la vie.