In my experience, virtually all JRPGs have a high potential to go out of print rather quickly and jump in price. The market's a little more balanced out than they used to be - you won't see anything disappear as quickly as Valkyrie Profile and Shin Megami Tensei: Nocturne did way back when - but it's still a good idea to prioritize a bit.
Most recent Tales games seem to be pretty readily available though, outside of Limited Edition stuff, and we rarely have to beg and plead for even just the mothership titles to come to the US/EU.
Xenoblade was really kind of an oddity, in that Nintendo pretty much sold it with absolutely zero confidence. All marketing came from Operation Rainfall, it was exclusive to GameStop, had a microscopic print run, and was immediately OOP. Nice profit margins for Nintendo, but also really short-sighted, and I think that game is probably the key reason they're suddenly making a push to build up a diverse library on the Wii U early in its lifespan rather than near the end of it.