I rarely buy NES games anymore, because I basically have everything I want. "The complete set" as they say, except across all regions, and without all the garbage shovelware. There's only a handful of the more spicy titles left that I still don't own - Cowboy Kid, Young Indiana Jones, Over Horizon, Cosmo Police Galivan and a few I don't really remember.
But some times there are games I just didn't consider previously, for various reasons.
The Ultima series, of course, is mostly at home on PC platforms, with the console versions being massively simplified - "dumbed down" even. On paper that's not really ideal for a series that's notable specifically for its complex underlying systems.
Ultima 4, however is a game that's often highlighted as one of the better NES RPGs, and I think most people would tell you that this game and the original PC/Apple2 version are two entirely different games, and I feel like my exploration of the NES library isn't really complete unless I've played it. Playing it without playing any of the PC Ultima games beforehand does feel kind of dirty though.
This is also one of those annoying games that aren't particularly "expensive" as just a single cartridge, but which are only available as an import - so with shipping and customs and everything, it ends up costing three times as much, more expensive than any modern PS5 game would have been And I feel like I'm gonna miss the manual for this one particularly.