Used Truncated Atomic skis
This is a pair of super beefy Atomic skis that I cut the tips off of to see how they would work on a skibike. They do work, but with no sidecut, all your turns have to be skidded. They don't carve at all like shape skis do. But if you are looking for the cheapest pair of skis around, just to get you out there, these are them. They are already pre-drilled for mounting to any 40x40mm hole pattern and they come with the mounting screws.