Technically he doesn't need to double his sales to go gold. There's a misconception that RIAA certification has everything to do with soundscan numbers. Well, depending on how technical you want to get, it is based on sales, just not the sales people think.
It's possible for Tech to sell 200,000 copies of the album and still have it go gold, if there are 50,000 copies sitting on retail shelves and such. RIAA doesn't go on sales of the album like Soundscan does. Soundscan tracks how many copies are purchased by customers, they ring it up in their computer, that's +1 for Soundscan. They ring it up, that's +0 for RIAA tracking, because the copy has already been added to their total.
RIAA goes on units shipped, not necessarily sales. That is, unless you want to get technical, since for those copies to be shipped, they have to be purchased by retail stores before they can turn around and sell them for profit.
Though yeah, Killer is a ways off from Gold, because it needs to reach 250,000 units shipped, and it it's not moving units in stores, then those stores aren't going to bother ordering that many copies. If Killer switched numbers with Absolute Power though, it would be gold, because the last number I saw for AP was some 296,000 or so.