Personally I think that borders on the obscene, practically hoarding. I'm the sort of "collector" than just buys, never sells, and as such I look for variety, try to avoid duplicates without practical purpose. I can understand the fun in finding and restoring, but if I was building up duplicates for just the sake of that activity, I'd take a different approach and move along the extra pieces instead of letting it build up like that. Perhaps he realized how insane things were getting and decided to make a break.
To be clear, I'm not criticizing this guy or anybody else here who may resemble him, I'm just expressing my opinion about my personal approach to collecting. People are free to do what they want and I certainly don't begrudge them that right. As long as you're not hurting others, whatever makes you happy is fine by me.
Not seeing the actual listing, it sounds like he's only selling it as a single batch, right? If so, good luck with that. Buying a pile like that would put someone from a novice to a complete collector without all the fun getting there. A buyer would have to be somebody with the intent of reselling the individual pieces for a profit.
Then shipping cost for such a mass of iron would be prohibitive, so he'll need to find a CI reseller close enough for local pickup. Who happens to see that ad. Good luck.
I agree, though, that's a pretty cool picture.