Suggestion about retainers - Let us buy a perm one

A good while back, SE mentioned that players would be able to 'get more retainers' due to them not having pre-planned extra item space/armory space

What I'm suggesting is this: SE, offer players the option to make a one time purchase for a retainer, that we get to keep. Not any of this annoying as bloody hell 'pay per month' thing.

The price would be about $30 (This is USD, prices would vary depending on country and soforth)

This retainer would stay with us for good, BUT only on that one character (Like with other optional items in the cash shop).

Current price for a retainer for me right now is $2/mo, and with the $30 fee that would equal to 15 months of prepay before it would eventually be averaged out to less per month.

I've been playing since 2.0 was offically sold in stores at about August 27, 2013, so I've been playing a bit over two years now, and 'rented' a retainer since they gave us the option to, and I believe this would be a nice thing for players.