Wondering if anyone can offer advice?

Currently got a GT Grade Sora "Gravel bike" mainly used on roads & canal paths cycling to and from work.

Recently 3 spokes broke (think pothole related) so I got it fixed & serviced. Cleaning bike today found I've another broken spoke. Is it worth repairing them as they go? Replace them all? New wheels? Budget is tight & while I'm still pondering a mountain bike for bikepacking on cycle to work scheme I've limited funds for constant repairs with the labour costs involved at the moment!

If three spokes on a wheel of mine had gone I'd likely just replace them all.

However continuing to replace them individually is a good plan too and easily done without recourse to the bike shop if you can get the cassette and the disc off. This happened to me on a cotic wheel - it broke half a dozen over a year and then none thereafter.....

Yup, I'm with Scot on that — they're probably all going at the elbow, which suggests they're reaching the limit of fatigue, possibly under-tensioned for your weight.

If you're able to lace up your own wheels then a set of spokes is about £20; if not able to build your own then add on £20-30 for someone else to rebuild it for you — either way it would be well worth it from my point of view.

I reckon the wheels on your bike are just machine built and come stock on many bikes of that price bracket. They could not be well tensioned or stressed and may be built using economy components. This may lead to the failures you are experiencing.
The best way out, as Colin says is to replace the whole spokeset. This will work out far more cost effective than having individual spokes replaced as they brake.
The obvious thing to do is to get a new, decent set of wheels but you have already stated that you are on a limited budget.
Good luck!

Thanks all! Seems a trip to LBS for full replacement of all spokes then. I figured this was most sensible option but pleased I asked just in case!