I paid £375 (I think) for my Kiyo when I bought it in Japan, and that was was in pretty good condition. I think that Nags and Kiyos are similar in the NJS heirachy, but Nags are generally more popular outside Japan than Kiyos, so go for a bit more. I'd say that - depending on what tubing it is - you're probably going to be looking at £450 - 600. More if it has real pedigree.
I paid £375 (I think) for my Kiyo when I bought it in Japan, and that was was in pretty good condition. I think that Nags and Kiyos are similar in the NJS heirachy, but Nags are generally more popular outside Japan than Kiyos, so go for a bit more. I'd say that - depending on what tubing it is - you're probably going to be looking at £450 - 600. More if it has real pedigree.