CF3 V1 owner here. The Epic line is everything these folks have said they are. They are truly remarkable speakers as they can play any musical genre you throw at them; and play it damn well. As previously stated, they are silky smooth and laid back - unlike any other Klipsch product ever produced. I feel this is why many in the Klipsch community detest their existence. On the flip side, they do have a strong following as well. I highly recommend that you at least give them a listen, you might discover you can't live without them.
If they are V1's.....they are worth the asking price and worthy of your consideration IMO. So long as the drivers are in good shape, the cabinets could be rehabbed down the line. Roy Delgado captured lightning in a bottle with the CF3/4 V1 making them one of the best products to ever come out of Hope. As Moray has said many times - "If Roy Delgado touched it......you should be interested in it". There is much validity to his logic
As klipschfancf4 has suggested, measure the ports. You want to see that they are longer than 2.5". If they end up being 2.5", all is not lost. You need to take a peek at the internal wiring and see if they are colored wires or translucent (like the first generation cable offered by Monster Cable). If it has the Monster type wiring, they are V2's and could easily be brought to V1 specs by simply changing the port length. A quick inspection of the serial number would give you an idea of which version they are as well. You want to see "49" in the 4th and 5th digit indicating they were built in 1994. They would at the very worst be V2's if this were so. The first 3 digits are supposed to represent the day of the year in which they were built.
And to reemphasize what GPBusa said - CF3's would be a major upgrade over your KG4's