a radiator replacement could be a DIY repair. Time is about an hr or so. Seek on-line for a replacement. Some have located and installed all metal ones. I replaced mine a couple of yrs ago and installed a Modine which is similar in design to the OEM (plastic tanks). I bought it because at that time the on-line source (CarParts.com) was having a 30% off sale. You should be able to procure a quality aftermarket one for under $200. You should replace the thermosensor and its gasket. You will need to remove and reglue the foam seal from the OEM to the new. Now would be the time in which to replace the thermostat, radiator cap, and the A/T cooler hoses. And if you have not removed the bracket attached to the upper radiator tank holding the Cruise and Throttle cables, do it now.