eBay industrial surplus sellers are your best source for low-cost, high-quality chain. The particular chain I referred to in my original post was 10' of Tsubaki #50 chain (not 50-2) with a Buy it Now price of $16.99 for a 10' strand new in the box.
Regarding tires, I spent over a month shopping the internet. I finally found an awesome deal on 9 Carlisle Chevron tires for $58 each, plus very reasonable shipping to me here in Alaska.
I'd have to dig around to see where that source was. I forget who I ended up getting them from, but I remember the great deal!
Planter Bob