This type of building was delivered to the site on the back of many flat bed trucks. It was then assembled, panel by panel to create what you are looking at. So, if you are interested in preserving this great old station, you will first need to have a slab of concert poured, with the correct attachments in the cement to accommodate the panels.
You will need to carefully disconnect each panel, marking each as to where it belonged and continue this all around and above the station. Unless you have a lot of money to hire people to do what you want, it will be too costly to continue. In my opinion, the cost of this building should be around $1.00, assuming you agree to accept all liability in the removal. The assumption here is that if they want the building gone, they will have to pay someone to remove everything. For $1.00 you will accept that responsibility.
Before you go offering any money for the station, be sure to check anything in the floor and what is it connected to. If for any reason they had a gasoline tank under the station, walk away quickly.
A quick story here in the St. Louis County region: One large oil company was spreading stations all over the place. In a community near where I live the purchased the "V" shape corner. An old building was torn down to make room for the station, but off to left of the "V" was what used to be an old Taxi garage. This little business was large enough that they had there own gas pump and with a tank in the ground for the gasoline. Well, after the new company purchased the land they started digging down to put their own tanks in the ground, they discovered the ground they purchased was filled with old gasoline, It virtually covered the entire "V" shape of the ground. One day that I drove by when they were preparing the ground, they were removing dirt from a hole that was at least 20 feet down.
I don't know who paid for all of this, but as a precaution, don't accept any liability having to do with the removability of anything that is in the ground at the station. Your picture does not show enough information as to where the pumps were, therefore I cannot determine where the tanks were in the ground. Notice, I said where the tanks were. By Federal law, not local, not state, but federal these tanks were required to be removed by, here I think, 1998. If the tanks were removed, the concreate is usually another color and east to see.
In the last two years at an auction where an old visible pump was being offered, they just casually mentioned it was still connected to the tank in the ground. Again, these pumps and tanks were required to be removed around 1998. I remembered the time, all kinds of pump were being offered, you just come and remove them. In my opinion, most of the old tanks are still in the ground.
Good luck, but be careful.
Jack Sim