The vagueness of the CL ad raises suspicion for me.
No mention of how it runs high points or low points. Also it appears the front end has been worked in, so look closely at radiator, from frame rails, etc. The paint also seems suspiciously shiny in this pics.
Renix era can be a challenge, but with the help of Naxja local chapters and the OEM Tech, it isn't too difficult to work out all the bugs. You can fix a lot of things easily enough and parts are readily available. Plus the aftermarket/upgrade modifications are abundant.
Personally, I think if the body and interior are clean, fluids look good, most everything works and it drives well it would be worth more than $1,000.00.