Charging for retainers was planned for the original 1.0 including a leveling system that went unused yes, but they did double the previously announced fee and they only increased their inventory by 25 slots in ARR, so not really enough to justify the extra buck. The main issue here is we can't mail items to alts and this makes the RMT excuse come out as dishonest to try and hide a cash grab, there's also the issue retainer levels reset each time you change their classes so you can't really cover all 4 venture types on a single character, although technically this won't be a major issue if the rare items are tradable instead of U/U with the help of a trusty FC bank even with the inconvenience of leveling an alt, at least for people with multiple alt slots but it'll also be an issue for people who only pay for one character. IIRC there was some sort of plan for a mega retainer to transfer items between multiple characters in a server, though it might have misinterpreted, again it was debunked with the good old RMT excuse, even though they're still running around shouting and telling every day.