Factoring is usually always more expensive than it sounds
For a few percentage points, selling receivables sounds like a great way to increase your cash flow. Depending on the collections reserve, you can net 75% to 100% of 1-months worth of cash flow... immediately.
However, this is a one-time bump. So you really have to associate lifetime costs against that immediate cash flow. And the reason we say lifetime, is because hardly anyone ever buys their self out of a factoring arrangement.
So if your horizon is 5 years, and the cost is 2% of monthly invoices, you are paying 24% a year for one months worth of money. If your reserve is 25%, then it is even more expensive. In this case, the true cost would be 30%.
It's like taking on an equity partner that never goes away.