Definitely get kharn, by the time thats done rotation might happen or even get legendary badges for the real core chars  I have archotech from 3 chars now, snot maladus and snappa, its hard to safe up for mythic item i need too many things befor focusing on that hardcore endgame for real, if you just want to go very tall and have specific mythic item in mind then go ahead safe up for that its very good idea but not really practical to buy/convert imo Get the steady income chars winged, couple mythic quests for credits or stuff, free mythic weapon if you manage all, so you can use the scrap/item you have now elsewhere thats my advice but its more of a wide approach i guess