The new added slots are way too expensive to buy a bunch just to see a marking that may be disliked. If we wanted to pay 1gb to be surprised, we already have RMA's, but having to buy 6 slots or so just to see whatever new mark has popped up in slot 16 is kinda unfair on everyone. And it's also a feature thats either ''Go hard or go home'', and it can force you to dive right in.
So I suggest each mark slot after 10 could be 1gb, and you could select whatever slot you want - still paying the fee, but reducing the expense of having to buy your way up.