There was a time when agencies charged 10% commission. As agencies were constantly recruiting new agents to increase their market share, competition in the industry was created from within. As more agents were competing for the same stock, one of the issues that occurred was commission rates that were being discounted to obtain listings. Another issue was that agents listed property deliberately over market value just to obtain the mandates.
About 6 years ago, commissions were at 7.5% when the IEAA tried to fix this rate for their members, while 5% is pretty much the norm at present. Some privateers advertise ridiculously low commissions, but they don't remain in the market for long and they never create the possibility of a budget to go big. Every business has operational costs to cover and employees have to make a living from the business. The lower the commission rate, the more strenuous it becomes for a business to survive especially in the present economical times and when lower priced property is moved.

In order to compensate for low earnings from low priced properties, one might consider to apply a minimum commission of R25000 to R30 000 per transaction, irrespective of price for all properties sold below R600 000. (It is the same work to sell a property for R300 000 than it is to sell for R900 000). By properly explaining this principal to both sellers and purchasers, you should not find any resistance in applying it. This principal ensures that the agency can maintain your businesses' profitability and that you do not suffer an imbalance between income and operational cost.