$150 for a new, cheap/small digital oscope that supports an X/Y mode. Yes, it's not truly a vector display, but accepts vector x/y input and rasterizes it. No

$150 for a new, cheap/small digital oscope that supports an X/Y mode. Yes, it's not truly a vector display, but accepts vector x/y input and rasterizes it. Not all of these have an X/Y mode though, so check first. But, yes,old oscopes with CRTs is an option also.