United and Delta have San Jose SJC to Amsterdam tickets from $456 to $495 round trip for travel from January through March 2019.
United Airlines San Jose SJC – Houston IAH – Amsterdam AMS – Toronto YYZ – Denver DEN – SJC
$458.93 round trip Sat March 16 – Sun March 24
I found this same itinerary for $455.76 on Momondo.com.
Delta Airlines San Jose SJC – Salt Lake City SLC – Amsterdam AMS – Los Angeles LAX – SJC
$494.53 round trip Mon Feb 25 – Tue March 5
I’m seeing some SJC-BCN tickets at about the same price on at least oneworld airlines for certain midweek dates over the same time period. I believe the fare rules indicate that you have to stay at least one week.