I put my residential prices up every year by a little bit at least.
If you have plenty of work, put the least profitable up by the most, that way you avoid being a busy fool, doing loads of work at low prices.
Better to do enough work at high prices
Example if you had 10 houses at £10, and you put them all up by a £1, and you lose 1 you're still making £99 for 10% less work.
I always increase work that's in a row by a little less because of time saved by not having to pack away and move.
Bigger commercial contracts are harder to increase. You could risk a £1000 a month for an extra £50 a month. Trust me I know whereof I speak... :