The players have arrived
Upon hearing Aster's words, Natasha and Charlotte immediately closed their bottles with the corks again, most of the time elixirs lost some of their effectiveness by being exposed to the atmosphere, or with the pass of the time.
So, they put the corks on the bottles and kept them in their spatial rings, while they both gazed at Aster.
Though the rings they gave him were indeed expensive treasures it was a matter of perspective, the process was relatively new that's why the demand was high thus making it overpriced, but it was a situation that would change in a couple of years.
The divine "elixirs" Aster handed them on the other hand, were lifesaving graces, which everyone has, is and will be struggling to get.
A universal cure/healing type elixir that can be used in a critical state, without any prior preparations and that also patches up a meridian or even the dantian, for someone in the "Mortal" realm is priceless.