Upload & Sell: On
You say it's a bit overpriced -- how much?
The motor drive is nice, but it makes that body into an ungainly monster. There used to be a lighter weight winder with grip that was better unless you need blistering speed.
I started my photo career with an A-1 as my first camera, and owned an F1n a bit later. Nice cameras, but I still think the T90 was the better FD for technology.
I recently bought a EOS 1N with the Power Booster grip, for a ridiculously low price (under $200). Like your EOS 3, I can use all my EF lenses and get better metering than any FD body ever had, including the F1n. I currently have an AE-1 Program, T90 and the EOS 1N for 35mm film cameras, and prefer the 1N.
If you just want it as part of a collection, get it. But for a user, I think you should look around on eBay and Craigs List and get an EOS 1, 1N or 1V and get the most out of your film experience. Canon still services the 1V.
If you do decide to get an F1n, check around more. You can get some really good prices if you are patient and keep looking.
Best of luck on the hunt!