I'll have to say upgrading to indexed shifting on an older bike is a great way to go. I changed my Schwinn LeTour from friction to bar end shifters for about $100. I found a set of shifters(Shimano Ultegra) on E-bay brand new in the box for $65.00, a 7 spd.Shimano freewheel (most older bikes have freewheels instead of cassettes) for $20, and a Shimano Tiagra rear derailleur for $15. The bar ends still use friction on the front so you don't have to change the front der. It works great and very comfortable to shift. And since I only paid $50 for the bike at a thrift store, I've got a great shifting,reliable,comfortable and fairly light bike for under $200. So if your thrifty and fairly mechanically inclined it can be done.