If you like second-hand bookshops, visit Hay-on-Wye. I'd recommend crossing the Atlantic to see it even. It's in south Wales, and it's a whole village of second-hand bookshops. Many are huge, some are tiny and very specialist (horror, detective fiction, etc.) Every year I spend three or four days there browsing and reading, and doing some walking in the mountains as well.
I've had Hay-on-Wye on my radar for a while (I'm Dutch, so it is a doable holiday destination by train and bus). The surrounding area looks interesting as well, and the mountains certainly appeal to me. You make it sound worthwhile. How are the prices? London's second-hand bookshops seem to be notoriously overpriced (not surprisingly due to rent and costs). For now the only things holding me back are the fallout of B…
I don't think I've ever really considered the prices. They're always just 'a few pounds'. Doesn't seem necessary to worry over it given how good the experience is.
If you're buying genuinely valuable or rare older books over the £50 mark I might stop and think, but I'm usually not browsing for that kind of book - I'm already looking on AbeBooks etc.