SS 14g 36er Spokes breaking

[Rowan]

Is anyone else breaking way more spokes than they should on their Coker?
I've hardly broken any spokes until I got a 36" built with 14g spokes (the heavy steel ones are still going strong). Firstly the bike shop said the nipples are crap and they got decent brand name nipples instead.

After riding my wheel for only maybe 1000km (which isn't that long for a 36") I started breaking spokes. I only had 4 extra ones and within another 1000km I've been through 6 and had to buy another set of spokes to replace them with (because it is a custom length that the bike shop can't get). I'm not doing anything too strenuous on it- like riding slowly with a bit of shopping and accellerating slightly and "Ping". The guy at the bike shop says the reason is not his wheelbuilding but he blames the cheap no name spokes, since they are breaking near the hub end. I imagine the forces on the wheel are massive compared to smaller wheels but I don't think they should be breaking so much.

I'm planning to build another wheel sometime soon and I was just wondering if anyone else is going through spokes like there is no tomorrow. I guess it isn't a big deal as spokes are as replacable as seats tires and pedals.