long ago in the month of May and before the energy costs were as you said cut in half... the problem was that the progression a new player with 0 star equipment to get to 5* gear was much too fast

in about 2-4 weeks a player could get endgame gear and start mass producing gear to give/sell. This wasnt what OOO wanted since it would cut the longevity of players playing SK much too short and flood the market with gear meant to be hard to get

3* stuff if generally more expensive because thats the highest star level one can trade freely since items that are bound remain bound even after upgrading them (4*and 5* need to be at a certain heat level to upgrade which means they need to be bound)