I tried the local paper route here in WA when I first started collecting, but I only ever found Amiga 500s. There just isn't enough equipment out there in my local. I hope it's better on the east coast, but you have to remember the Amigas, beyond the stock standard 500, are uncommon to rare here in Australia. The only guy still selling Amiga stuff here on the west coast is that Amiga Innovations guy, and he charges like a wounded bull. Quite frankly ebays prices are cheaper than his prices.
If I see a 3000 in good nick around Marcb I'll let you know, but the chances aren't good. In all my years of Amiga collecting I've never seen a single 3000 for sale here.