Thanks mate. Roughly how much are we speaking? Might be a bad time!
Not sure on second hand prices mate. High end laptops are quite rare beasts generally speaking.
With this sort of scanning work, and the capture, processing, and display of the data, you cannot get away with cutting corners. You need a strong CPU and a strong GPU, with a shed load of RAM and fast and plentiful hard drive storage. Realistically, you are looking at 2400 quid and upwards. You need a decent sized screen as well on the laptop... no point in trying to work with the 3D data on a 13 or 14 inch display, unless you also carry a second monitor around as well. Probably better 17 or 18 inch display.
Also, you will be burning through battery charge if not plugged in the mains during scanning/capture. Beware poor battery capacity or dodgy secondhand batteries. Run it plugged in if possible.
Having just had a quick look online, I would expect to be paying 2500-3000 quid on current prices for a laptop that will comfortably do the job. RAM prices are outrageous, CPU and GPU prices are outrageous, storage prices are ridiculous. 😪
EDIT: that is based on buying new