My opinion is that Colorado is the last one to build points in. That state is about opportunity and you use it as your state to learn elk hunting in (or Idaho or Montana). The best tags there are 20 plus years of points away, and just not worth that time when you can do better elsewhere. Again, just my opinion, but there you have it. That said, I am building points there just because I am building points for deer and it doesn't cost much extra to also do elk. Deer though take a lot fewer points to draw a good unit.
Arizona, Wyoming, and Nevada are, to me the best places to build points for an elk tag. Washington and Oregon also have some worthwhile tags. Utah is another, but tags are hard to draw and take a lot of points so I put it last on the list. New Mexico, I apply in every year and hope to draw since there are no points there. I pulled a 34 muzzleloader tag there a couple of years ago. Very fun hunt.
Any of the best units in any state for the best seasons take max points (usually 18 plus). However, you could hunt good units in say, Arizona, every 5-8 years (luck plays a role here to some extent). Or you could wait 20 for one tag and hunt MT or CO every year while you wait.
Really depends on your wants. I build points in every state, and want to hunt more often, so I apply for good units, but rarely the best. Even the good units have great bulls, and the best units still don't have a lot of great bulls. My goals are to hunt more places and have a good hunt. A 400" bull isn't my goal. A 300ish bull with a good story behind it is. Then again, I might get lucky and tag that 400" toad.
Jeremy