I have heard this one is very good, but I've never used one myself.
http://www.indoorspecialties.com/index1.html It doesn't quite meet your $$$ requirement, however. Hey, take note of the description - "Can be used to cut tapered spars"...... It's only 24" long, though.
Oops, just realised that gets you to the main page only. Select "Tools", and then "Micrometer Balsa Stripper"