In the comments on Arid Mesa, a very good point was made by a reader. If these get too high, too fast, we're likely to see a bubble scenario occur. If this is the case, and these lands go totally berserk, you want to be on the inside of the bubble, not the outside. There's going to be a lot of Zendikar product being opened over the next 3 months, especially with ZEN Sealed being a PTQ format for the fall/winter season. They shouldn't cost more than 10-12 dollars. They'll start at 15. They might hit 20, and when you see the scale tip well towards 20, that's when you pull the trigger and blow your fetch lands out.

There's a chance that they'll stay 20 for a while, but let's be real. You don't have an Extended PTQ for months, and that's when you'll REALLY need them. You'll survive FNM without buying into 2 or 3 playsets of overpriced lands as long as you heeded the advice of QS and stocked up on Tri-Lands. If you can ride the bubble to profit, do so. DO NOT get emotionally attached to the idea of "having fetch lands". You'll probably have an idiot friend who brags to the world how he finished his set already, but he won't tell you how he traded a Baneslayer for 2 Arid Mesas. Don't be that guy.

The concept of value investing and value trading cannot be stressed enough, and it will be covered a bit further in the Zendikar Pre-Release Guide, but the basic concept is as follows. Invest in multiple copies of low-cost, high potential cards. Think of them like Magic's penny stocks. A card like the recently spoiled Lullmage Mentor is a great example. They're a dollar on Ebay, so 3 playsets will cost you less than a single fetch. If a fetch land goes from 15 to 20, you've made 5 dollars. Woo. If Lullmage Mentor sees ANY play whatsoever, it will jump from a dollar rare to a 3-5 dollar rare. Even assuming you only triple up, you're generating almost FIFTY DOLLARS of value. That's why it's the rocket fuel of Magic trading.

Value trading doesn't have to involve cash in and cash out. When Sygg, River Cutthroat was a crap rare, a certain QS editor snagged about 12 for under a dollar a piece. Two days later, when it appeared that Sygg was vital to the Jund Cascade deck that swept GP Seattle, it was effortless to trade Sygg at 4 or 5 dollars. Imagine trading a playset of something that's pre-selling for a dollar like Lullmages for a single fetch land. It's like buying the card for 4 dollars. Hopefully this brief example demonstrates why it's ideal to use your resources very carefully at the pre-release. A lot of prices will change very quickly, so be mindful of when to buy, sell, trade and just sit still.