Thank you all for the replies. Even $10 for an 1989 Donruss card...that'd make it probably the most valuable card in the case (of 3,240 cards).
I honestly expected the answer to be more in line with what cardinalcollector said...something like "it's worth 25% of a regular 1989 Donruss Dave Smith card".
I may go ahead and list it on eBay and see what it brings.