I was actually thinking the 30% payback was the amount you had to pay back... so if you're running a business and you get this $5K loan and then sell the results for $7100. Here's what happens:
$7100 * 30% = 2130 => how much you must immediately pay back on the loan for what you borrowed
$7100 - 245 - 2130 - 5000 = $-275 => amount in your pocket
$5000 - $2130 = $2870 => loan balance
So you borrow $5K, buy $5K of inventory and ended up with a $275 loss AND still have a loan balance.
This is why I don't think it's such a great deal unless your markup actually pays down the loan AND leaves you with a profit.
Let's try a 100% markup:
$5K loan, $10K sales.
$10000 * 30% = $3000 => how much you pay back of the loan
$10000 - 245 - 3000 - 5000 = $1755 => amount in your pocket
$5000 - $3000 = $2000 => loan balance
So you borrow $5K, and at the end of the transaction you have $1755 in your pocket PLUS a $2000 loan balance you still need to pay off. So you're still net-negative.
I just don't see how this is a good deal without a MUCH higher markup... and 100% is a damn good markup on most things.