How much does it cost to make an FOI request?

At least £84 per request according to this site FOIAcentre, not one I've come across before, but not the first I'm sure of many companies who will mirror the US approach in offering a commercial service. I wonder if such companies will be at risk of having requuests aggregated together under the fees regs (S5) or having requests classed as vexatious or repeated under S14 .