Which stainless spokes to get?

I bought a 700c wheelset from america a few years ago (sunrims) and the wheels have only done about 1000 miles, now every time i ride the bike (average 5mile rides) it snaps a spoke. The spokes are stainless, i dont remember the brand name.
I never bounce up/down kerbs, and always check tyre pressure at 110psi before riding. The tyres are michelin dynamic classic.
I've been biking 35 years and never snapped a spoke. I have 4 other road bikes (and a mtb) i regularly use and never snap spokes on them either. Most of my other bikes still use 1980's wheels and spokes.
Is this common with modern spokes, i.e. Are they all flimsy crap nowadays?
Can anyone recommend me some decent durable stainless spokes that are affordable, or should i get non-stainless which seem to be stronger?

Sapim Race are my preferred choice.

Spokes snapping on a low-use wheel like that is almost inevitably poor build technique

Check the size of the spoke holes in the hub in relation to the spokes used If they are not a snug fit you are onto a loser. Spokes working in hub holes will guillotine off the heads ,poor quality build could also be adding to the problem .Used to be able to get washers to fit under the heads if still available may help if that is the problem

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Snapping spokes as you suggest is usually one of the following

Poor wheel building

Use of second hand spokes when building

Wrong gauge spokes, ie using 15g spokes in hub holes big enough for 14g

Rim is fubar'd and someone has tried to rectify the situation by having different tensions around the wheel

Also, the more spokes, the less likely breakages - 36 will be more durable than 28's. Stick to 3 or 4 cross patterns on the rear wheel, don't try to copy what you see on modern race wheels which are designed differently

The stainless db ones from cyclebasket are excellent value. Built many wheels with them for road and mtb.

Re:

DT Swiss Competition are excellent spokes.
Good quality spokes can be reused multiple times in several builds without problem, it's component compatibility and quality of assembly which count most.
Get Roger Musson's book "Professional Guide to Wheel Building" if you can, it's a superb resource.