I buy a case at a time from these people (
https://www.justgloves.co.uk/Nitrile-Gloves/Top-Glove-Powder-Free-Blue-Nitrile-Gloves-AQL-15 ). Needless to say, a box disappears into the boot of the car, the garage and anywhere else messy jobs can occur, but, I find a case will still last me a few years.
It probably shouldn't need to be said but I'll say it anyway. I supply any visitors to my apiaries with a fresh pair of gloves. It's important to create a barrier between apiaries (mine or theirs). I'm not too picky about changing gloves between hives in an apiary as I'm often working on several hives at the same time. Drones are readily accepted in hives other than their own anyway so, I reason that, if there ever was a problem, I could contain it at the apiary level. Fortunately, I have never had any disease and I live in a low-risk area. Incidentally, brood abnormality is one of the things I look for at each inspection.