Proofreading Rates, help!

Hello everyone,

I have just got my first offer of a proofreading job and i'm very unsure of what fee to quote. After much research on the net i've found the recommended rates by the SfEP, etc, but am not sure how many pages i can finish in an hour.

Can anyone give me an indication of how many words and pages a proofreader will generally read an hour? I've seen 8/10 pages on one site, but also 5 on another.

I haven't seen the proofs either yet, so would rather not estimate price before having seen them, but think I will have to give an estimate to secure the job.

Also, do proofreaders generally charge per hour or per word? I know the SfEP recommends per hour, but a lot of editors advertising online seem to quote per word, and i'm way of undercharging and finding the job takes longer than i'd expected.

If it helps the info i have is that it will be around 100 pages of A4.

Any tips from someone a bit more experience than me welcome!

Thanks