Hi dgunmac - and welcome on the Gauge!
According to a
German website with informations about old-time model railroad stuff, your Märklin 3093 has a collector's value of 85-90 Euro - that's about $70-75. (This is a minimum value, and the price you could get for it - say at ebay - could be MUCH higher! And I presume, that your loco is in first class condition, complete with the original box.)
The prototype of your loco was the famous "Baureihe 18" (series 18) of the Deutsche Bundesbahn (German Federal Railways). It was a four cylinder Pacific, 'born' as the Bavarian S 3/6 - at her time simply THE high speed passenger locomotive. With her pointed smoke box front and the wind-splitting cab she was considered by many as one of the most beautiful engines ever built.
Hope this helps you a bit,
Ron