Value depends on your location and your ability to market. All original often means has not been maintained in 40 years. I buy "all original" bikes all the time. Anything with bearings: wheel hubs, headset, bottom bracket, pedals, will need to be disassembled, cleaned, and fresh grease. These tasks mean the buyer has to do the work themselves, as the cost to have a shop do this work will be several hundreds of dollars. Then you have rubber parts, like brake pads and tires. Add chain, freewheel clean, flush and re-oil, fresh cables and housings.
When I obtain bikes like this, my first step is a complete tear down to the bare frame. Then I clean, replace bearings, fresh grease, and the process begins. I have two in the queue right now. One is an all chrome vintage MTB with zero rust. Even though I bought it cheap, I won't make any money on it.
In my market, an all original Super Sport from that era will bring $25 to $50. To the average buyer, $50 will buy a used bike that weighs at least 10 pounds less, with much nicer components (like a three piece crankset and a much better derailleur set). Schwinn spec'd in some really low end parts on these bikes, except for the Brooks saddle. It's kind of sad, as they knew how to make them better, but by the 1970s, they ran the business on auto pilot, not upgrading anything. When the Japanese bikes started entering the market in the early 1970s, it was an eye opener.
Years ago, I sold one for $250. Those days are long over.
Hopefully your market is better, but, I have bought a lot of bikes in the Denver market as I found that market to be very soft. Hopefully you can do better.
Denver market right now:
Trek 900: $30.
While a Trek 900 is a MTB, for a recreational rider, I find these old school MTBs provide a lot of value. Great brakes compared to the SS, can take a myriad of tire widths, 26 inch tires are plentiful, can handle any rack front or rear, better shifting, list goes on and on.
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