Hi Sean
Welcome to the forum, loads of good guy's and gals on here always willing to share there Knowledge.
You should have picked up a lot of good tips from someone who's been wc for 21 years, all except putting prices up.
Just tell them your new price and if they don't like it dump them, they will soon call you back when they know they won't get a four bedroom house done for £10
I had the same problem when I took over a large round that two old guy's ran for almost thirty years, the prices were way way to cheap to make a decent living with.
I took the bull by the horns (so to speak) and gave the really cheap one's two choices, some I lost and some tried to get back on my books for the above reason, But I would only take them back for the price I gave them. some did and some didn't, there loss not mine. go for it and good luck with your new venture. 'O' and Merry Christmas.