I've seen uncut housings priced higher, but I don't see very many of them sell at the higher prices. A virgin housing will occasionally sell for more, but usually only when the buyer is desperate. A few years ago, they were selling for $400-$500, but not now.
As far as clusters, I have ten untested '71-'72 small block clusters I'd be happy to sell for $300 each. I watch Ebay all the time, and I never see them bring more than $300 unless they are restored. Someone would be crazy to pay more than $300 for a used cluster that wasn't tested. Circuit boards are $75, the small gauges are $75 each (repro or repaired), tachs are $150-$200 (repro or repaired), quartz clock conversions are $125. I have yet to see a used cluster that doesn't need a circuit board, amp gauge, and clock repair... and that's $275. I see restored 5K clusters for sale for $600...why would you spend $450 for a used cluster, then have to put at least $275 into it when you could buy a fresh unit for $600.
Again, I watch Ebay and I never see the '72 gauge harnesses sell for more than $150 unless they are restored. I have several in "take out" condition that I would sell for $150 each.
When you have a package deal like this, you're not going to get top dollar for every part.