Just wanted to give an update on this deal:
I was one of the lucky few who was able to purchase before it went OOS. Total with tax for me was $57.XX. This is AMAZING compared to buying new. It arrived today around 11am and I immediately tore it open hoping to not have a used filter sitting in stinky water. Fortunately it looks like it was never actually used. The o-ring looks new (lubed up), the media and filter pads were all unused and new in plastic bags, and all tubing and fittings were included. As mentioned the instruction manual is all but worthless but you can easily figure it out yourself or go to youtube (though I recommend against some of the practices I saw and I'll detail at the bottom how I primed/etc.). Total time to setup for me was a bit under 2 hours, but that is because I was triple checking everything I was doing AND I had to replace existing HOB filters (first needed to make sure everything worked, then disassembled the filter to add my old filter biological media).
The only issue that had me initially REALLY concerned was a couple of the plastic tabs near the top of the canister were snapped off. These hold the motor to the plastic top and are strictly AESTHETIC, as in they do nothing for actually creating a seal between the filter and the motor. There was still 3 out of the 6 or so intact, but honestly these do absolutely nothing. If any of the metal tabs would have been bent/missing I would have immediately returned the filter since those are the only thing preventing the canister from separating during operation and flooding your floor.
OK so if you're still reading here is how to prime the system in 30 seconds without having to suck on anything and risk making a mess. A quick recommendation on how to orient the quick disconnects. On the outlet (ie the smaller tube coming out of the top of the canister), look down the barrel of the quick fitting you will be putting closest to the filter and make sure it closes when you pull up towards the ceiling. If, like me, you ever need to reduce the flow of the spray bar you want the curvature of the valve to be smooth. Putting it in the orientation I recommended will do this, in the opposite direction you will cause unneeded turbulence that could shorten the life of the motor.
Connect the quick disconnects on both ends of the filter (the bottom is the inlet (fatter tubing) and what draws the water into the filter. Close BOTH valves on either piece of tubing (yes you only need 1 valve closed to prevent water from moving through the tube but when you use the quick disconnect you NEED BOTH CLOSED or else it will leak. Sounds obvious, but I almost made this mistake since I had only 1 closed for most of the time while I was measuring/cutting stuff.
Now take fatter piece of inlet tubing (cut to length and fully assembled with the plastic screen to prevent fish from getting sucked up on one end, and the quick disconnect (in the OPEN position) on the other) and walk over to your shower and fill as completely as possible (you will need to keep both ends at about the same height but have the u-tube sideways so you can fill it as much as possible). When as full as you can manage (it won't be perfect but it doesn't have to be) turn the shut off valve to the CLOSED position. You should now have it 3/4 full and this will be more than enough to prime the pump.
Go back to your tank and install the inlet tubing in the tank trying not to spill water. Then connect the inlet tubing quick-disconnect back on the filter. You should now have a fully assembled system minus the tubing that goes from the filter back to the tank (smaller tubing with spray bar). What this allows you to do is let the siphon work with no backpressure that would stall the siphon. Grab a bucket and put it next to the outlet valve (you can tilt the canister if you wish or just gently bend the short piece of tubing from the quick disconnect valve on the outlet so you don't make a mess.
Open the valve on the inlet side (outlet at the top is still closed). Nothing should happen if you have a proper seal (a couple bubbles is OK), but if there is a sudden rush of water close the quick disconnect and check your seals. Now you have a lot of water pressure wanting to rush into the filter so SLOWLY open the valve on the outlet side and you will here a rush of air, the water level in the tank should go down, and soon you will get water coming out of the outlet valve (hopefully into your bucket). I would personally recommend draining a couple gallons of water from your tank and discarding this. Even with cleaning the media you will still get some particulate that I personally don't want in my tank.
When you are satisfied with the water coming out close the shutoff valve on the outlet (smaller tubing), connect the spray bar assembly, and open the shutoff valve (all valves should now be opened). When you do this there SHOULD be some air that gets pushed out of the spray bar since it is equalizing. Don't freak out.
Wipe down all tubing and the canister and check for leaks.
Now you can plug in the filter (with a drip loop of course!) and check for leaks. If you primed properly there should be very little air left in the top of the filter and so it should be almost silent. I gently tilted the filter this way and that to get any bubbles trapped at the top and now my filter is virtually silent. It's creepy really. I've had HOB filters for all of my hobbyist life, and the quiet is something I'm going to have to get used to (as previously quiet meant a failure or a really bad leak).
The other really cool thing is the surface of the water is now like glass because the spray bar is near the surface facing down on a slight angle (I inject CO2 and so surface agitation is something you try to keep to a minimum). All in all I'm happy as heck with an awesome canister filter for cheap.
HTH anyone and please feel free to ask questions if anything is confusing.