I also would vote for fixing up your old bike since you like it, maybe upgrading the rear derail, it will feel like a new bike. If you can find a Ti saddle on discount (Nashbar) that
really improves the ride. I just upgraded my 90 Peugeot this way & the difference is dramatic. I upgraded the wheels also a few year ago.
If you have a bike you like, upgrading over the years is an alternative to buying new bikes. You can get one or two new parts a year & it doesn't have to cost much.