Just got quotes from some tradesmen for a job. "A" came round to quote and spent an hour and a half poking round, testing things out, considering all sorts of possibilities. Some of what he did was the sort of investigative work you'd expect to pay for, and I tried to pay him for it, but he insisted he'd do it at risk and just asked that I bear it in mind when the time came to award the job. "B" came round to quote and immediately identified exactly the solution that A settled on, and was in and out in 5 minutes. A's quote is 50% higher than B's, and I have no reason to think that A would do a better job - they both come recommended, and I think that B is simply faster. I really should pick B, but I can't bring myself to let someone down who did me a favour, even though that favour wasn't worth the difference I'd pay. Help me find the strength and the words!