Gaea's Cradle is arguably the best mana-producing land in Magic, in stiff competition with Tolarian Academy and Mishra's Workshop. Unlike those two powerhouses, however, Gaea's Cradle is legal in Legacy, a format poised to grow in the coming years due to Eternal Masters. Like those cards, it's on the Reserve List.
Gaea's Cradle is a solid $150 and shows signs of stepping upwards to at least $250 apiece (no way this stops at $200 once it pops). If you don't have one (as I don't), and you've wanted one for ages (as I have), and you're interested in Eternal formats (as I am), now may be the last time to get one below $200. Even a beat-up copy is a great investment, especially if you're expecting to play Eternal for the long haul. This is exactly what everyone else is thinking, which is why it's such a good spec over the next couple weeks.
The Judge Foils are extremely tempting, but I think in their next impending price movement they will be greatly hindered by the $500 price-point. They will be lucky to hang at all above $500 in the near-term; it's such a strong price point. Jumping from $380 to $500 is nowhere near as tempting as jumping from $150-$250, and present data shows more pressure on the non-foil anyway. Also, the sheer scarcity of these cards and their Reserve-list status will serve to narrow the price gap between the Judge Foil and the Original copy over time as people just want any copy to use.