The website has more information. There are 3 stations. The lowest priced plan has a per-minute usage charge and the more expensive plans include a set amount of minutes each month after which you pay the per-minute usage charge. I believe this is to discourage someone from hogging a site and not allowing other people to use it.
The big deal is that part of your subscription includes (it's on a lease!) an Elecraft K3/0.
Picture from official website http://www.elecraft.com/K3-Remote/k3_remote.htm
The Elecraft K3/0 is a remote control for an Elecraft K3 transceiver. It doesn't actually have any RF components inside. It's meant to pair with a standard transceiver and give you the feeling of being there. I'm unsure if you can do so without using the RemoteRig box as well. It's the smaller box sitting on top of the two K3s above. The purpose of that box is to pass control signals and audio between the Remote and the Transceiver boxes and it can also work over the Internet as well.
Prices to buy this stuff at Elecraft directly
Elecraft K3/0 price $695.95
RemoteRig price $499.95
Cable Set for each side $49.95/ea
So roughly $1300+shipping+K3 transceiver to set this up yourself.
That doesn't include the price for amplifiers, antennas and the cost of the location and other overhead for things like power, network connectivity, cooling/heat and so on. The yearly price is very expensive (The top end could be a house payment) but once you figure in all of that stuff it quickly becomes obvious why. Trying to figure out if this is worth it to you really comes down to if you can do it cheaper or not, if you can do it at all or not, if you can get by with less of a system (I think most can, really), and if it gets to be too busy to be worth it for you. I can well imagine someone using all of their monthly allotment of time during a busy contest and that putting others out. Frankly, to me, it really feels like the equipment should be a buy and not a lease. You're already paying well over the purchase price for the equipment they send you even if you pick the lowest priced plan. I'd like to see this addressed with a policy for Bring Your Own Devices giving a lower monthly cost at least, if not a lease converting to a purchase depending on the plan and the length you subscribe as with cellphones.
Makes me want to try to put together something similar using Raspberry Pis though.
Just a disclaimer, my views are my own and don't represent the views of any person or company mentioned in this post. Nothing precludes you from having a home base and one of these services. I'm not even advocating for it, just another aspect of the hobby.