Mrs nbt here.
It may seem to you biking guys that curtains are indeed expensive.
You are paying for the fabric (decent fabric costs over £15 per metre).
Lining and making up.
If you buy good quality hand finished curtains they will last many years. Keep out drafts (saving money on fuel bills), noise and light, they afford privacy too. And most importantly of all they will hang properly and look good.
Even if I wasn’t a professional curtain maker I wouldn’t buy from the internet. Instead prefering to get decent ‘ready made’ curtains, which could be taken back if fitting incorrectly or not doing their job.
Oh and shop around.
I work for myself, so am cutting out the middle man, from say Laura Ashley of John Lewis, who will all have at least 20% more on their price.