As a woman, I own quite a few pairs of shoes in a variety of styles.
For flat pumps, I wouldn't break £30. My most expensive pumps are Iron Fist ones, and they were £25.
For trainers, I'll pay up to £70 for a pair of Vans, because I know they'll last me ages. My current ones were £45 or so in a sale 5 years ago, and they're still going strong.
For heels, it depends on the brand, but most of mine are Irregular Choice or Iron Fist (so I'm paying for very elaborate styles), which are generally £70 or less. My husband bought me some platform heels for Christmas, and they were £60.
For boots, I've got some cheap-ass ones which were £25, but I'd consider going up to £90 for a really good pair. I'm currently lusting after some Iron Fist ones for £85.
What I don't get, is people that shell out hundreds of pounds on plain, boring, strappy shoes, just because they're Christian Louboutin or Jimmy Choo. If I'm splashing out on shoes, I expect them to have an exciting design.