The "Deluxe" moniker gets you the fan and the little knob at the front of the tube for swinging it around.
If you could get it for $300 I'd be all over it! You'll see them on Cloudy Nights for $275- 350 all the time and that's for pickups only. Shipping such a big thing is CRAZY. It's probably worth $400 as well but there's gonna be a few things you'll add right from the start, so less money for the scope the better.
You're gonna need to pick up a nice laser collimator (not off amazon!) and perhaps a 9x50 RACI finderscope. You're about to go DEEP considering the upgrade from the 90mm refractor and star-hopping in the 9x50 is so easy!
There are other things you'll eventually want, like a coma corrector, especially if you start buying 2" wide field EPs, but that can wait and may not be necessary at all if you keep your EPs under 70 degree AFOV. I use 82s for my widest AFOVs and use the ExSci HRCC and it's pinpoint stars all the way to the edge. F/4.7 is right at the edge of needing a coma corrector. The longer you have it the more you'll see it.
Outside of that, I LOVE mine. I have others but this was my first "real" telescope and I'll likely never sell it. If this one looks like it been cared for, no issues with the mirrors or the action of the alt/az, I say get it.... Good luck.