I know, such a riveting question 
We rent. The house came with curtains, horrid flowery things which don't fit the windows at all and aren't lined. There are no nets. This is an ex military area and so there is only very small wire fencing between gardens making everyone's garden overlooked.
When it was colder and darker the curtains didn't cover all the windows and were draughty. Now in the summer with people in their gardens later, people can see in as the curtains do not cover all the window. So I bought two pairs of really thick, lined curtains from matalan as they were half price. £30 for two pairs of good quality curtains to enable me to sit in the living room without the neighbour being able to watch tv with me from the garden behind.
DP is not happy as we didn't "need" them. We aren't rolling in it ATM but we aren't exactly on the breadline either. I've boxed up huge amounts of stuff for a car boot where we can easily make this £30 back but he's adamant I'm being frivolous. I'm not though am I?