Greater Good is a Legacy and Commander draw engine that I have long admired from afar.
Sacrifice outlets are in Eternal demand, and green is the regular customer. Draw is the lifeblood of Magic, and green is typically only meddling. Consider the synergy with front-loaded creatures, death-trigger creatures, discard effects... lots of holes to stick things into. This is a very appealing build-around.
Urza's Saga and 9th Edition are the only printings and 9th Edition has the only Foil.
It's high time I get a few:
The last time Greater Good spiked (which was it's first significant move in history, if memory serves...), it jumped from $3 to a solid $8 per card. I think the proportional jump will be comparable this time around, within the next month or so. So this means up to $20 or so.
Non-foils are the better bet for proportional gains: Foils are already $50. A Foil pricetag of $100 is likely within a year or two without a reprint, but I'm looking for better specs than that. Namely, non-foils.
Get a few of these non-foils around $8 soon, pay the premium for NM (this is a new tactic of mine). They're headed to an easy $15 within a month or two, maybe $20, and have a strong, albeit conservative, long-term outlook thereafter.