"Too long for fiber" ????
No such thing. Multimode fiber can reach for a few miles or so. Singlemode can run for several dozens of miles or more.
How far do you actually need to go? If its within the same building, I think it is likely to cost less than you think it will.
Here is a 100 meters (>300 feet) of OS2 9/125 (singlemode) with dual-LC at each end for $50. That's less than that network card would have cost you.
Add a pair of matched SFP+ adapters and you're set.