[rexf]

Do you think that cash transactions are unavoidable?

Players sell accounts, power leveling services, items, gold, etc. There are always people who are willing to pay real cash for virtual things. Without fundamentally changing the game, you can't get rid of people meeting on 3rd party (or in-game channels) to trade cash for in-game goods/services.

As a player, it's acceptable for Blizzard to aggregate the market in-house and take their cut of inevitable monetary transactions. If they change the game to encourage spending real money to get ahead (like battlefield heroes?), then I would stop playing. If they are responsible about it (only acting as a clearinghouse, but not affecting balance mechanics), it isn't a problem for me.