Several years ago I did some freelance work installing biomass boilers for a firm bases in Montrose.
We had a domestic job local to me in Surrey and the boss came down with all the bits and tools necessary to do the job except he left his SDS drill at home, so we bought a massive cheap one from B&Q for 38quid. It worked and at the end he gave it me as a keepsake.
Since then it has been knocked about a bit, used for demolition and general fixing by the brickie at work and though it weeps a bit of grease and he has lost various bits it's still going strong.
AJH