Yes, of cause? If you can't pay for the support you need to provide then you need to raise prices. Imagine a logistics company complaining that they would be overwhelmed by the cost of fuel.
But of cause Upworks has no benefit to raising prices for their services, as that would make competition harder.
If a logistics company most of the time didn’t need to buy fuel and sometimes just didn’t deliver if it required too much fuel, plenty of people would still use it if it were cheap.