Yet another onion set thread

Last year many of my cheapo (poundland) onion sets bolted. The seed sown ones, whilst smaller, didn't.  I'm planning on sowing some seed onions today to give them a bit longer growing period than last year.

I noticed D T Brown advertising heat treated sets at an eye-watering price compared to Poundland or Home Bargains.  What's the team think of heat treated onion sets and have you used them to advantage.  TBH no matter the advantage I can't see me forking out £9.70 for 160 ish sets plus p&p when I can get the equivalent for a couple of quid. Plus I don't need 160.