I think you might need the fenders if the rust is bad enough, by the looks of it in the picture there is rust at the lower part behind the front wheels (where I'm assuming the fenders go). The body kit itself will most likely be some obnoxious looking thing that would cost a bunch to get painted and fitted so probably not the best money spent on his part.
But by the looks of the cheap taillights (not calling them cheap because they are Altezzas but because they looks like they are fogging up from not being sealed properly), the springs and fenders are probably no-name ebay items. Nothing against ebay but, some of those cheap springs sold on there ($40 shipped link below) have horrible ride quality and end up blowing the suspension ending up costing more in the long run.
I would buy them if they are branded (H&R, Dropzone, Tein, Skunk2) because they would make a nice aero mod for the vehicle. 
Either way, if there is minimal fixable rust and the car is in working condition, buy it but I would try to negotiate on lowering the price just to see if it pays off. It would make a nice eco-vehicle
I would buy springs if branded and fenders if needed due to rust. 
Another thing, I would ask if he still has the stock taillights.
http://cgi.ebay.com/ebaymotors/88-89...spagenameZWDVW