What's a reasonable offer on this?

[Buenaventura]

Hello,

First, I didn't know if to post here or in the Classified sections, since I'm not trying to sell anything.

I found a converted bus that is really calling me, but I think the asking price is way too high... 15k (CND) There is no plumbing or electrical, and only the front fall of the bus in insulated. I'm estimating a minimum extra 5k of work on the interior.

https://whistler.craigslist.ca/cto/d...608011894.html

What would you say is a reasonable offer that I can propose to the seller?

Thank you,
Sebastian