Tainted Aether has two printings, Urza's Saga and 7th Edition.
7th has a Foil, Saga does not (juuuuust missed it). 7th foils are notoriously the highest Foil multipliers of more or less any set. It was among the very first to get the Foil treatment, and the print run was very low.
The movement on the Foil here going to be intense, from $10 to god-knows-what: $40, $60? Buy any 7th Foil Tainted Aether under $20 like it's going out of style, if you're the patient type.
The non-Foils are the more short-to-mid-term spec, here. Anything under $1.00 is a good deal, as we're looking at an easy $3.00 in a few weeks, and possibly higher down the line as more and more creature-less decks come of age in Eternal formats.
This could see a reprint in a Commander deck, but it's a low probability for the next two offerings. Further, after the initial price hit, it would rebloom like cut herbs, as we've seen again and again with old powerful clunkers that get included as reprints in the new Commander releases. The beauty of the Commander reprint is that it's a one-of in a sealed product, being Commander and all. This limits supply of the reprint significantly but can catapult the card into the contemporary Magic zeitgeist.
Online marketplaces are about to run dry of both copies in "bulk" status. Eat 'em up.