I hate to tell you that 70K one way was probably the very best price you would ever find. DL mileage tickets for international J are OUTRAGEOUSLY expensive unless you happen to get "lucky" to find one for a decent price.
One option to consider is to look for mileage tickets departing from other airports nearby and see what comes up. You can just a cheap coach ticket on Delta to get you there, but be sure to leave a nice long layover in case of delay. Suggest you search SLC-AMS, SFO-AMS (on KLM) and SEA-AMS.