I've bought a few Suburbans over the years, anywhere from $5 to $15; mens style only. Women's style has essentially no value, men's style not a lot. I've stopped buying them as the market has gotten a lot worse over the last several years. Really heavy bike with bottom of the barrel parts. Condition is everything, all those steel parts are rust magnets.
All original? That means cables, housings, tires, bearings, grease, chain, freewheel, brake pads, etc. are all almost 50 years old. Stuff wears out, rubber dry rots, brake pads get rock hard, grease dries out, and everything requires maintenance. Only a D-I-Y'r could make this work out as it will need a thorough rebuild and new consumables. In the bike world "all original" = needs a lot of service work.
Really only suitable value wise for someone that wants a Chicago Schwinn. While Schwinn made some fine bikes in Chicago, they made many more really heavy and really basic bikes. IMHO, its one reason Schwinn went bankrupt. They were too slow to improve their product, and once the Japanese entered the market, they were caught way behind. Then they decided to solve labor problems by closing their plant.