I look at the overall cost of labour and cost price of materials then think what am I happy with sticking on the materials, what can the customer afford
I would say a min of 10% but the skys the limit, in b and q wylex RCBO's are nearly £ 35 quid each, wholesale I get them £ 10.99 + vat, ok not wylex but an RCBO non the less and decent quality
I worked in a shop yesterday and the owners were moaning about the last spark who did the lighting
it was a good job to be fair to his install, they were moaning about the cost
he installed 6 T5 twin 5ft fluorecent fittings
2 double sockets cable surface enclosed in conduit, not big run - small shop
total bill came to over 3 grand!!!!!
he charged them £ 300 per light and over a grand in labour
he was there less than a day, and I priced the lights wholesale out of curiosity and they were £ 105 each plus VAT
no wonder he drives a range rover!!!!!
I could NOT charge those prices and sleep at night!!!