You can call Mini-Circuits at 800 654-7949. They do sell in small
quantities. I've been meaning to order some of the
ADE-5s for awhile.

I just phone mini-circuts up directly and order straight off them (here in the
UK). They have a minimum order value of £25 though - but it's easy to reach
that figure with a couple of devices.

Have you tried contacting them direct ? ... give them a ring.

Clive