Have to agree with Darran.
Recently gave a price to a housing association for residential building with a mixture of 2 and 3 storey (mostly 3). £510 for 205 metres of gutters so about £2.50 a metre. I thought that was more than fair.
Turns out I was 'far more expensive' than the cheapest quote. The guy who got the job was a plumber with an omni.
Because ladderless gutter cleaning is still quite new there doesn't seem to be any common pricing standard. My best work is still domestic where I can charge £35 - £60 and be gone in 60-90 mins. The problem is getting enough of them (for me anyway).
Still, it's early days and I believe that ladderless has a great future.