Not sure if Web Site is accurate or current... but shows they have new.
dji-s1000-frame-hexacopter
Glad to see your adventurous side for a S1000. If your Profile is accurate on age (diff on Inspire forum), you've missed sUAV development years. Your Mavic PRO will fly totally different than large platforms, and the S1000 had it's touchiness on landing stability. A large Octal or Hex tipping is quite the experience and pucker factor if you're used to a Mavic PRO size platform.
Have you thought out the electronics, wanting to leave with older electronics or upgrade to A3 or A3Pro. There's some nice features of the S1000, but there's some negative too. If you watch eBay, you'll come across a S1000 occasionally. Adorama was selling S1000 kits, A3Pro and Lightbridge2 kits until last year or so... I think they drained the "new" supply. IF you use a new A3Pro / LB2 setup, you have essentially same setup & compatibility as the M600Pro.
I have 2x M600Pro and a S1000 in project build up. The payload mount & rail width is slightly different than the M600Pro, needing a little modification or can be changed over to nice 3rd Party Tension Spring attachment system. The default S1000 was a 15" flexible Prop and the motors & ESC's weren't nearly as smooth as M600Pro... this gave the S1000 a little bit of a bad name as not being very controllable or smooth.
I've got 2-3 (8 each) Sets of the E1200 TPS Motor upgrades, targeted for S900 but works same for S1000 Octal. The E1200 TPS kit moves craft to 17" (or 18" can be used) Carbon props, Greatly increases tuned motor smoothness and improvements in the ESC units. If you add this modification, you"ll need longer motor arms for prop clearance and need the A3 or A3Pro / Lightbridge 2 electronics. Also longer legs help too when folded.
The increased Prop Dish size, stiff carbon blades, smooth ESC, and lower RPM Tuned Motors... enhances the overall flight smoothness of the S1000. I collected the E1200 TPS kits from multiple Countries, so if you're interested I may be interested in selling 1 Set. I had originally collected 3 sets because I had visualized making a few custom S1000 for sale... that later faded in appeal due to cost and the difficulty finding all the S1000 components needed.
For ease of completion, I'd suggest examining the M600Pro. The Ronin MX or Gremsy Gimbal hold the A7 series nicely. The end result will have a lot more User Support and parts on-going. If it's a Octal you want... then yep, the S1000 is an option.
Designed for multirotor copters weighing 7-15 kg, the E1200 Pro can be adapted on platforms with 25mm-diameter arm tubes, such as the S900. Extensive optimization provides efficiency, safety, and endurance under extreme conditions.
www.dji.com