This should make the 6s pretty enticing for bargain hunters, especially if you know where to look. Obviously, Apple no longer sells the compact oldie directly, and neither do major third-party retailers like Best Buy (at least as far as unlocked variants are concerned).
But if you don't mind purchasing the device in refurbished condition with a 90-day warranty included, you can pay Woot a visit right now and cough up as little as $119.99. If you have some extra money to spare, though, it's probably a better idea to spend $129.99, $139.99, or even $159.99 on a GSM unlocked model accommodating 32, 64, and 128 gigs of data internally respectively.
Naturally, the entry-level configuration comes with only 16GB storage space, which may have been enough for some people four years ago, but it's definitely a big compromise today when it's not doubled by a microSD card slot for external expansion. In terms of color options, you get plenty of those as far as 16, 32, and 64 gig variants are concerned, but the 128GB model comes exclusively in a gold hue at the heavily discounted aforementioned price.
The deal is good today only, mind you, with a few hours left at the time of this writing, and the AT&T and T-Mobile-compatible iPhone 6s units on sale here are expected to have a "moderate level of wear and tear including (but not limited to) scratches, dents, and dings." Bottom line, these won't look quite as good as brand-new devices, but they should work flawlessly, having been rigorously tested from that standpoint.