From what I recall, they were originally from Earth-X and migrated to Earth-1 after the Nazis were wiped out on Earth-X. A later retcon in All-Star Squadron said they were originally from Earth-2 and went to Earth-X.

You made a few leaps in this paragraph. I will say no more about this topic.

I've seen the model you're describing--it's the "Comics/Read One Today!" with Spidey, Supes, Archie and Richie Rich (the "another character" ). Here's an article about someone who was able to get it for dirt cheap when the mom and pop store he'd bought comics from since the 1970s went out of business:
www.iowalivingmagazines.com/2014/01/22/toy-stories-7/


But barring that sort of situation, when I've seen it on Craigslist or eBay, it's usually priced anywhere from $200-$500.  

Correct. They were originally assumed to be from Earth X but retconned as having travelled there from Earth Two along with several other heroes in All-Star Squadron. They briefly moved to Earth One after Earth X was liberated from the Nazis, but were back on Earth X by the early eighties.

Why? I loved that story.

My period of being a diehard X-Men reader ended before Chuck Austen's run started. However, I do own a few issues from after he switched from Uncanny to plain X-Men (dropping the New from the title) and I do have some sense of the disdain for Austen's work from my time on the X-board at the old place. Thus, for the most part my recollections will be second-had, so I might mis-describe things I've only heard from other people.

One issue was that readers felt some of his plots were just dumb or abandoned what we knew about characters. For example, I remember complaints about revealing Nightcrawler's father to be an actual demon. Granted X-Men is a superhero comic with fantastic plotlines, but I think folks like the idea of Nightcrawler being a deformed person rather than a supernatural being. It undercuts the idea that his different, but human.

He also introduced a character named Nurse Annie (the nurse at the Xavier school), who I believe was widely disliked. She became involved with Havok, after Austen made Polaris go nuts, two developments which many fans disliked. Supposedly, Nurse Annie and Havok were an effort for Austen to put his relationship with his own wife in X-Men.

I believe fans also complained about how he dealt with romantic relationships in generally. He paired Angel with Husk (Paige Guthrie), which fans didn't like, maybe because of the age gap or because it was out of left field. I seem to recall fans complain at some point he depicted some X-Men having sex and ignoring an imminent threat or otherwise behaving irrationally.

Part of it may be that his run on Uncanny overlapped with Grant Morrison on New X-Men and suffering by the comparison in fans' minds.

I tried to jump back on to X-Men during the Milligan run, and decided to go back and read the handful of Austen issues after he jumped from Uncanny to X-Men. I didn't find those issues particularly bad. However, there may have been a couple of mitigating factors. That last arc was more or less a big fight, so that may mask the above flaws. Plus, I liked the Salvador Larroca art.