Put it up on Sedo or another service with a reserve price of £450, and invite the guy who approached you to bid there. A buy it now price might also make sense.

Put it up on Sedo or another service with a reserve price of £450, and invite the guy who approached you to bid there. A buy it now price might also make sense. I'd go for £2-4k for the whole set. Remember you're not selling it to cover your costs, you're selling it because they're valuing it at more than you value it.