On the subject of buying stuff for DIY (not breakfast), I can add:
In general I find the trade-orientated outlets painfully over-priced and staffed by people who would not be allowed to work in B&Q, Wickes or the like. Occasionally, and only occasionally, it is different. These week I tried to buy a slightly unusual Honeywell actuator for a valve on an underfloor system. I had the old one, so the part number was clear and I had tested it away from the system to confirm that it was caput. I e-mailed Honeywell and they gave me the names of the two largest outlets - normally suppliers to the trade.
At major outlet number 1 (maybe the larger plumbing/heating group), the man at the counter said he hadn't a clue, it wasn't on his system and he wasn't sure. I suggested that he contacted Honeywell since they had given me his Co's name. Grudgingly, he 'phoned and came back with, "Yes, Honeywell has them, they're =A324.40 inc. VAT". "Please, order me one, I'm happy to pay in advance so that you know that you won't be left with it", I replied. "Oh, did I mention the =A325 charge, 'cos we've got to order it", the surly sod added. My reply involved sex & travel
I 'phoned major outlet number 2, and asked again. "Don't see it on our catalogue but give me a little while and I'll 'phone you back". An hour later he did call back with the good news that he'd have in by the next day. Price the same =A324.40. When asked if he wanted payment in advance he said no. When I collected it all I had to pay was the price quoted. The intelligent employee even asked what it did and how it worked so he'd know next time. When I told him about the other outlet he laughed and said that he used to work for them and that it went on all the time -- they just made prices up to rip-off non-trade customers with special charges etc.
The second supplier is PTS part of BSS. I will get all my special plumbing stuff from them in future. I'll not name the other place but I'm sure lots of people know who they are. Naffer