Can you rent? I bought a dewalt one for about 100 a year or so ago. Tried using it. Put it in a cupboard and have forgotten about it until seeing your post.
I bought a Stanley Cubix for £50 on the recommendation of the guy who fitted our kitchen worktop. He had a green line but I bought the red and its been fine
will need a laser level to mark out some internal insulation which it the go-to model from the usual places without spending loads?