I sell eComStation. I can sell you the final beta build eCS b2 2.2 (Dec 31) for the price of eCS 2.1. eCS Demo beta 5 is based on eCS 2.2 beta 2 from May, 2013.
Others have said ArcaOS is a much better idea. For your case, I agree with them. If you buy eCS b2 2.2 (Dec 31, 2013), it is pretty much unsupported. You are on your own.
ArcaOS 5.0 was less feature rich than eCS 2.2 b2 (Dec 31), but with the current ArcaOS 5.0.6, it is much better than any eCS.
https://www.blondeguy.com/computer/eComStationForSale.htmlThe only case where eCS is better is where you have a product based on eCS and you want to buy a license for one more copy of your product. In that case, ArcaOS is not acceptable. I have tried, but Arca Noae will not accept the order. As such, my largest accounts are eCS-only.