I e-mailed the company asking for a quote, they were fast to reply, accurate with their quote, and explained the process.
I took the glass into the shop, and within 5 hours it was ready to be picked up. The first time the glass didn't fit the cupboard, but I brought the glass + the actual door in, and he matched it exactly and put it back in place as I waited (15 minutes or less).
He said next time to bring the entire piece in so they can fit it properly - apparently our cabinet doors aren't quite square!
The receptionist & the fellow who cut the glass were friendly, and the glass quality is great - the price was less than we expected!