got a cheap digital onef rom aldi a few years ago when i started my xr2 restorattion,been spot on compared to mates expensive ones but battery only lasted 1 year.....but they give you a spare! cost me about £12 and worth every penny
aldi ones at £8.50 are fine for most things you'll ever measure
if you need super accurate measurements you need something better than digi calipers anyway (generally)
Ive owned both expensive[£100] and cheap[£7]
The cheap ones dont lock off properly and the reading can move slightly,not critical as it only moves .+/- .0001. But annoying none the less and totally unsuitable for precision work.
Wish id never flogged the good ones
I have a fair few sets and the battery that came with it did drain quite quickly (you also see it bulge on the backside with the writing on when they run down)
But I have a plentiful supply of Silver Oxide SR44's so until you mention it I never really thought of it.