The most expensive jeans that I bought was around $30 too, but that was a rare event. I don't usually buy jeans that are above $25 since I'm not brand conscious when it comes to clothes.
I think the most I spent on a jeans was about 50 pounds. Now I would never spend that on a jeans as I am more thrifty now. Now I spend about $30 on a jeans...the most important thing is that it fits me properly.
The most I can pay for jeans is just $30! Not worth buying a more expensive one as they're all the same. You are only paying for the brand's name that's why it's expensive. Even the cheapest one can be of good quality, so not paying so much would be great.