Where to buy good automotive wiring?

To be honest I am not sure how much I have in it, I built the rack and probably have $20-$30 in that (wheels and clevis pins), the wire however I probably have several hundred dollars in at least. Wire isn't overly cheap as I am sure you know. I bought packs from Amazon and eBay where I would get like 4 colors of a certain gauge. I usually had to get a roll of pink independently.

All that said, this rack has been indispensable. I also have a HF bin setup where I keep wire pieces and old wire. I also have a cabinet where I have all of my connectors (weather pack, packard and metri pack).
Where did you purchase the rack itself ?