They're only £1 a bag Kaz, and tbh if you're cooking for two not bad value.
If I chop them in my mini-chopper instead it's even worse, as you take the lid off all that juice gets you
W/rose also do a bag of tiny-diced onion, carrot & celery mix, ideal for things like Bolognese especially if you don't normally have celery - we do but not when it's expensive.