I wonder if you couldn't do something incredibly simple like get some pressure treated 4x4 posts and use a router to make shallow slots for the panels to sit in. Plant them the right width and run a 2x4 along the bottom to let the panel rest on it.

What is it about solar panels that makes everyone want to use these really expensive mounting solutions? Is it just because they're trying to engineer a full 30 year lifespan right from the start?

You will still need the conduit for the wire of course, at least up to the inverter. That will add up pretty quickly if your mounts are spread out.