It's to give you a sense of achievement, and not so that you can buy all the most expensive items the day you join.
Obviously some of the higher-priced items are available with USD, like pure and void, as well as some other new additions like magma and others. Generally because the qi amounts are really high, so some players may not have the dedication to play 20k games of mp.
Like me.
It's also a nice profit area.