And AR's prices have come way down
You can get AR15's today for about what you had to pay for them in the early '90's. The main difference is that today, you have way more options to choose from than just Colt and Bushmaster.
There is only one company that makes the Mini-14. My opinion is that the Mini-14's will get more desireable as time goes on, and the AR15's will get dated and stale relatively quickly. Just look at some of the older versions of the AR15 - they have really fallen out of favor because they no longer look like what the military uses. On the other hand, there are some older Mini-14's that I'd rather own over the newer ones being produced....and some newer ones that look pretty fine.
50 years from now, if I were someone's grandchild, I'd rather have my grandpa's nicely preserved stainless steel w/ nice laminate wood stock Mini-14 over his Iraq-War era looking AR15.