It's an '84 (the '85 High Sierra has a unicrown fork). Most notably yours is missing the setback seatpost with extra QR that's depicted in the panel pic of the catalog.
Those eBay prices sound wildly optimistic. There was an '84 High Sierra that was tempting me in my local market that sat on CL for weeks and it was only $100, maybe $120. Perhaps in CA you can double that if you can find someone with early mtb fever. I never see these Schwinns getting close to Stumpjumper money.
