Where to find an exhaust manifold for the 8.1 L18

Hello all, I have a 2001 C3500HD (bucket truck) with the 8.1. It’s got cracked exhaust manifolds and I’m having a heck of a time finding a decent quality set of manifolds. There are Chinese ones on eBay with pretty low reviews. Amazon has a dorman but only the left side. Partsgeek, Napa, Oreillys, Advance, Autozone, and Rock Auto also only have the left side and want $400 to $980 for what appears to be the same $180 one on Amazon. What am I missing here? Are these old workhorse L18’s just left for dead at this point?

I would appreciate any suggestions. I’d prefer not to sink piles of money into what I consider to be a pretty simple cast part just because the truck is “old.” I mean, 2001 isn’t even that old as far as I’m concerned. I’ll fab a set up if I have to I guess, but that seems way overboard for what should be an off the shelf part.