It just so happens that I am currently building up two mid to late 80's Cannondales with Suntour and Dia Compe components. The thumbnail photo shows my L.L. Bean model Cannondale (Criterium?) I bought out of the catalog in 1987. I paid about $350 for it, if I remember correctly. It came with Suntour 3000GX derailleurs, Suntour's low budget line and friction shift only. If the Cannondale you are lookng at has Cyclone 7000 derailleurs, then it is Suntour's first attempt at index shifting with a seven speed freewheel. It should have the Suntour Accushift index/friction downtube levers. If it has Cyclone GT components, then it is friction only. Cyclone was Suntour's mid-priced line of components. The handle bar and stem are nice 3ttt alloy on both bikes. Hubs are Maillard alloy on Mavic alloy rims, 36 spoke.
The 2nd Cannondale Criterium I recently bought off ebay for $167. It has Suntour's 3040 Accushift index components. The Dia Compe non-aero brakes are nice. I'm upgrading the ebay bike to a high end Dia Compe aero brake set, and the LL Bean bike will remain non-aero with either Dia Compe or Suntour Superbe Pro levers and high end Dia Compe brakes. The ebay bike had a Sugino crank, and the LL Bean bike a cheapy. I'm upgrading both bikes to Sugino/Suntour cranks. Hope this helps.
BTW . . . just a note about cracks in the frame. I remember receiving a notice in the mail from Cannondale about possible cracks in the weld where the down tube is attached to the steering tube. They had some warning stickers they wanted everyone to put on the frame. I never did, and I've never had any cracks either. For $150 each, just buy 'em both! Sell the one you don't want.
1987 Cannondale