They errated the price on that weapon. My suggested fix is just to make burst a fixed 2k cost, doubling for each additional use of burst on a weapon. A +1 weapon with all 5 elements and 5 bursts would cost 64k + 62k (2+4+8+16+32) for the bursts instead of being a +11 equivalent weapon. The bursts do not make this weapon twice as good for twice the cost.