I disagree with the rest of the responders. The Schwinn Letour is a wonderfully desinged, classic bike. As long as the bike is in good condition otherwise, swapping the steel wheels for good alloy wheels is the single best upgrade you can make, and it shouldn't cost more than $60 if you re-use your tires, tubes and freewheel. Take a look at these:
http://www.bikepartsusa.com/product_...1&p=01%2D82957
http://www.bikepartsusa.com/product_...1&p=01%2D82958

I have heard good things about these wheels here on Bikeforums, and have seen them in person at the LBS,
and they seem like decent wheels for the money. For less than $60 bucks, you can seriously upgrade your classic ride. Letours are great bikes, and worth upgrading. Even if you decide to put on new tires, tubes, cables, brake pads and bar tape, you should still be able to do it all for little over $100 if you purchase your parts carefully. Keep the old steel on the road!