Diamond Voucher goes for around 600k-650k these days, Max Res Upgrade is (not as sure about this one) around 600k as well, I think. Haven't seen these sold as much.
I really don't believe they are that much now. Maybe when they were in high demand but not so much now. You can try to sell at that price but gl getting a valid buyer who's going to actually use it.
I've seen the diamond vouchers drop back down to 400k-ish lately. The max reses don't sell as much, but I think for more. Try searching for recent auctions. There have been some.
Sadly, max res's are extremely low right now, considering that a 100 or 200 vote bonus will give you the same benefit in the near future... Around 300k max
