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How cheap is "cheap" for you? Most PPCs (Pocket PCs) run around $200-$300. If you are looking to run Windows Mobile 6.5 on it then you'll be out of luck as most PDAs do not get updates nor do they have a strong community besides HTC (which has pretty much been focused on smartphones only).
I would recommend looking up a refurbished HP iPaq (the 200 series is decent). NewEgg had a decent deal on the 211 (refurbished) a few months ago but I can't seem to find any current deals or low enough prices