Hello all - I'm new to the forum and glad to be here

Some of the things I'm really interested in learning is how to better assess cards, design Legacy decks, and generally learn how to better identify combos and card interactions. I'd really love to learn how to play the game better in tournament settings.

So, here's my first question. I'm looking at various lands that produce 2 colorless mana, and I've focused in on the following three:

City of Traitors
Crystal Vein
Ancient Tomb

Given how fast Legacy is as a format and how powerful combos can be initiated with minimal mana, why is Crystal Vein generally considered substantially weaker than Ancient Tomb? Does the fact that is a one shot deal really make it that much weaker generally?

Similarly, City of Traitors is nearly 3.5x more expensive ($-wise) than Ancient Tomb. Why is it valued so much more than Ancient Tomb as well as being 10x more expensive than Crystal Vein?

If you were considering these cards for your deck, what criteria or approach would you take to looking at them?

Any thoughts are appreciated - thanks all!