Goes infinite with Saltcrusted Steppe and friends, if I understand it right? ... No, wait, no it doesn't. Hmm, there don't seem to be any lands that do go infinite with this.

Wording would need tightening a bit, assuming that this is meant to refund you if you spent that on an activation of Vitu-Ghazi.

Huh. You're right. There really aren't many poly-lands.

­Mishra's Factory technically is, but not to any obvious advantage. Ditto (Bl)Inkmoth Nexus, Forbidding Watchtower, Stalking Stones etc.

Hitting gatherer...

Oooh! Nivix, Aerie of the Firemind explodes! Or.. not, that taps too. Gah. ­Dark Depths is a bit terrifying too. (Again, not infinite - but who cares?)

­Eye of Ugin aint a bad combo either, though once a turn isn't infinite.

Will this work off Cycling or transmuting lands? That has possibilities too.

Annd... everything else has tap.

Lets Minamo, School at Water's Edge infinitely untap, though how that can be exploited is more a Johnny's delight.

You'd figure some land would give a creature firebreathing or something, but I can't think of one. Most lands tap as part of the cost, thankfully.

­Nivix, Aerie of the Firemind becomes actually usable. Which is quite nice. Dark Depths is one of the best combos, yes. (And nope, cycling won't work because in your hand it's a "land card", not a "land".)

Aha! JMG's comment about firebreathing made me remember Lavaclaw Reaches. There is an infinite after all! But one that already goes infinite with Ceaseless Searblades.

So... yeah, I guess we conclude this is fine :)

I originally meant it to add , therefore color-washing the mana, but adding the colored mana back is probably fine.
I'm not really worried about Dark Depths because Vampire Hexmage already broke that. :-)
The Minamo, School at Water's Edge combo could make Wake Thrasher infinitely large, or allow you to mill yourself infinitely with Mesmeric Orb.