Where do you draw the line? Should I legally be allowed to run my own League of Legends client that is current version - 0.0.1 since that's no longer available

Where do you draw the line? Should I legally be allowed to run my own League of Legends client that is current version - 0.0.1 since that's no longer available to players, and offer all skins/runes at a fraction of the cost to my user base? There is something of a problem here, but the solution (as ever) is not a simple one.