Pricing is market driven.
I work on the principle that in any given 5 day week, I can earn over 4 days and the 5th is spent doing quotes, surveys, material logistics.
So lets work this back from, say £35k a year.
weekends 52 x 2 = 104 days
bank holidays x 9 = 9 days
normal holidays = 20 days
Non earning days = 48 days
Total =181 days
So 365 - 181 = 184 days to earn the money
That's £35k / 184 = £190 a day required add the van £10 per day, add £5 per day tool wear and that gives a net income requirement of £205 which divided by 7 working / on site hours is about £30 ph
What does upset me is when the rate gets questioned.
The other week I was asked to do 2 x days work after doing 1 x days survey / research etc for a City lawyer who owns an Aston Martin, 4 houses and must earn £120k+++ a year.
When I quoted £250 a day + £200 for work done to allow for a lower cost solution he queried the quote and asked me if I'd reduce it. I refused and backed off, he chased my tail pleading with me to do the work,
I stated that I was insulted by his suggestion of rate reduction and questioning the value I offered.
The builder on site informed me that in the end he paid another firm £1100 (and that they 'stole' my design solution).
If people can't respect a trade person being ethical about prices, then I'll give them the big 'E'- I and many of my clients understand my value.