I currently have an FlyThisSim BATD for sale $6500, 5 monitors, desktop setup, with Cessna controls, USB connection for side stick
Yes, technically the letter has expired.
That means it is “technically” a game/toy, not an FAA-approved Flight Simulation Device unless/until you can get the FAA to renew the LoA for your machine. Without that, the time/events on it count for nothing with the FAA. Talk to Donn Heikkila at Professional Instrument Courses (800-I-FLY-IFR) to find out how he obtained a new LoA for PIC's 15 or so FTS-TT's which PIC continues to use under the new FAA LoA issued to PIC.
And if anyone wants to add the Cirrus, Diamond, or Beech aircraft modules to Rusty's Cessna-only unit, you'd best first try to talk to FTS to see if they are still selling them. Also, given the legal actions claiming failure to deliver sims which were already paid for, you might want to make the purchase COD. See also:
And yet, all that said, I really love giving training in the FTS-TT issued to me by PIC – it's an excellent training tool.