The
MERP valuations on the wiki are slowly building in accuracy. It is always hard when you start because you get those odd outliers that skew the prices. I hope though that prices helped and the links to the auctions served as a guide!
I have been watching
MERP prices a lot longer than the few months we've started on the wiki price monitoring and I think your list is quite reasonable.
Those that I think are low are:
Mount Gundabad
Gorgoroth
Lorien
Northwestern Middle-earth Gazetteer
River Running
Necromancer's Lieutenant
Mount Gundabad and Gorgoroth used to fetch prices closer to $70. I do sort of expect these ones to creep up as more auctions are monitored. Same with Lorien and the NW ME Gazzetter. Lorien used to go for a hefty price and I think $35 would be better for that. The Gazetter $40. River Running I'd up to $45 and Necromancer's Lieutenant to $30.
I think Grey Mountains and Forest of Tears are too high. There had not been a Grey Mountains for while and I think the $130 on the wiki is an anomaly. If more get listed they'll likely be in the $70 range. I was surprised with those recent prices in the UK for Forest of Tears - that module is quite common and usually sells for under $20.
I hope this helps! And I am very envious of your find. Many of those modules I still don't have after many years of trying to get them!!!!