Lost Odyssey is remembered fondly by early Xbox 360 owners because its a reminder of the time when the console held a lot of promise, exclusive games like Mass Effect and Blue Dragon were being released constantly and it seemed like the console was unstoppable. When Lost Odyssey released, critics seemed to think that the game was good but not great, however it started gathering a cult following and now its widely considered to be one of the best games of the seventh generation. When the Xbox One Backwards compatibility program was announced back in E3 2015, many begged for a Lost Odyssey release, and after more than a year it was finally released again on September 26th, 2016.
A couple of hours after the announcement, copies of Lost Odyssey were already rising in prices. To compare, a day before copies of the game were going for around 15 to 20 dollars boxed, but a week after the announcement a cd copy would cost you 30 dollars in online shops like Amazon or Ebay. Prices will probably balance again though, the same thing happened when Red Dead Redemption was available on Backwards Compatibility, but after a couple of weeks the prices went around 10 or 15 dollars.
Honestly, Lost Odyssey is a gem that deserves more attention, and the Xbox One version runs even better than on the Xbox 360, so if you had any interest in the game before, now its the perfect opportunity.