96 chevy blazer 4.3 4x4. wont start?

the other day started. Got cool out acting rerated.. now I start it,it just turns over and over.,.wont even try to start. Firing don't no,i don't believe so..i had a fule pump this past summer..the only thing it hasn't been tuned up in 3 yrs or more. Was gave to me I had to have a 1/2 shaft put in..also a ball joint and all braks...even without the tune up still started up..no just turns over.

The 2000 is going for 4450, its a from a private owner who is selling it because of a new vehicle purchase. The interior is fantastic, minor exterior cosmetic damage , radiator and hoses have been replaced along with the cooling fan.
The 2003 is 4880 and is at a dealership. When I checked this car out there was no cap for the washer fluid and the lo beam bulb was just dangling outside of the lamp. Everything else was fine and not really any scratches.
I have my mind set on the grey one , but im not sure still. I ran both vins and they are great cars with 140k miles. ( 2000 is white ; 2003 is grey)