Since 8.3 was launched the vendor values for the quest rewards have not been displaying when I mouse over each item. I have tried disabling all addons and still did not work as I noticed that this only happens on some of the realms that I play on. Would anyone know what is causing this issue?
I haven’t had your problem specifically but a similar one. One my Horde toons I could see vendor prices in the tooltip on items on the AH - obviously quite useful in some situations - but on my Alliance toons I could not.
It turned out to be out of date Auctionator, which I thought I had disabled, but apparently when you disable an addon it only does it per-faction, and I had to disable it again on my Alliance toons.