No. It's important to realize that we are dealing with a special group of people. We'd attract more of them if we don't charge market rate to begin with. Reputation is more important when starting a business.
I have little experience in microfinance but I wonder about the 50% rate that was noted so necessary this week's excel exercise. Vikram Akula, creator of SKS Microfinance notes in A Fistful of Rice that, "Local moneylenders charged exorbitant rates for their loans, usually 4% a month, but sometimes as much as 10%, which works out to 48 to 120%. At such rates, anyone who fell behind on a payment could never expect to catch up -- even just a couple of months in, your interest burden would already be so high that you'd simply enter an endless debt spiral." (italics mine) Is it OK to charge 50%, even if it is lower than the local moneylenders in this case? Yes, microfinance does need to be sustainable, but I believe investment in tech and achieving efficiencies in service delivery can have a greater impact on budget.