Mrs NBT makes curtains for a living. It takes her a while to make curtains nicely, so she charges for her time. She doesn;t charge a lot in over all terms, I am often frustrated that the time she spends doing measurements and quotes on top of the making means she barely earns minimum wage. Bear in mind though that her curtains are usually hand finished and made to measure rather than knocked up using techniques such as bag-lining.
The fabric often costs more than she charges for the time to take. I remember once going to help her measure a nice house for some lovely people, and loading the car with the material to take home as they’d already bought it – they’ve been regular customers for several years and just needed to confirm the correct measurements for the windows in the new house, rather than getting quotes from different people. Loading three rolls of pure cashmere into my 8 year old octavia mean the contents were worth something like six times the value of the car 😯 . The charge for the making was nowhere near the value of the car in that case, much less the value of the fabric!
Just as you can go to halfords and get a full suspension bike with disk breaks (sic) for £79, you can go to Dunelm and get curtains for rather less then you were quoted. However, you do get what you pay for. I’m not saying that £3000 is justified, but most people spend more time at home than out on the bike..