4/7/2016 - Another way to achieve "sacrifice this land for a card later in the game" is to make cards that eat each other when you play duplicates. It so happens the current legend rule handles this kind of interaction, so rather than reinvent the wheel, I made a common Flagstones of Trokair.
Common legends are a bit odd, but I'd argue it's as justifiable on a land as all the non-legendary lands that mention a specific location.
This cycle isn't as good in Limited because you'll rarely have more than two of them in your deck. Another option: Remove "Legendary" and give them all a keyword like
Crumbling (When ~ ETB, sacrifice each other land you control with crumbling, then draw that many cards.)We probably don't need this cycle to ever ETB tapped, because the ability being mandatory is downside enough when you draw just these. If it proves too much, we can insert a 'may' into the keyword (and then some ETBT clause).