Actually, having just purchased a Domino I had a couple of discount vouchers in my sweaty little hand, so it was more like £1350 after discounts (and prices have gone up quite a bit since then). My justification is that I do this for a living. Her justification for sending me to Coventry for a fortnight was the Kapex. Maybe it was the Domino that really upset her. Who knows?
I was taught to mark out with 2H and HB pencils (I believe they were Lakelands in those days, I might be wrong). Nowadays I use Stadtler Noris red and blacks and a pencil sharpener (a Kum double sharpener - no sniggering at the back!). Those Noris pencils will actually withstand being dropped onto concrete multiple times before the leads finally break; I've tried mechanical pencils a few times - the leads break too easily for my liking, they won't withstand being dropped off a scaffolding, they fall out from behind my ear or hook themselves on the arm of my specs but worst of all they don't work too well after being used to stir my tea.
Almost every apprentice I've dealt with for years has had to have one of those fat, useless lumps of wood (or "carpenter's pencil") pried out from behind his ear and replaced with a proper Noris pencil. Those fat things work well enough if you are putting a cut roof on, where accuracy is measured in 1/4 inches (6.35mm in new money), but can't hack it if you are fitting a door, or a kitchen or a doing a scribe. As your anecdote perfectly illustrates