From what research I've done, these were published after Avalon Hill stopped producing RuneQuest III supplements, which dates them to the early '90s.



Products | Moon Design Publications



These are the last original RuneQuest III items to be produced, Moon Design Productions only doing reprints (Pavis/Big Rubble, Griffin Mountain) of RunQuest II material.



Collectibility wise, a Glorantha lover might see value in them, and they are presumably somewhat scarce as there is little information on the Internet about them.  However, I cannot pin a specific value on them, because there is no data.



Best thing I can recommend is to check out the Yahoo RuneQuest groups and place feelers out.  They're likely to know more than I.