Finally someone who spells worse than me- super.
You can typicaly buy a used shock for 300-500 bucks. In most cases they will need to be rebuilt maybe another 150-250 bucks. Maybe the one on the bike you want to buy just needs to be fixed.
Dirt bikes are not a cheap hobby, be prepared to spend some dough on a 92. It will probably need al sorts of stuff fixed.
I tell young poeple ( I assume you are young) to try to convince Mom & dad to let you buy a new one so you can ride it and not wrench on it , but you will have to like get a job a and stuff....