After months of trying to keep my airplane stationary using short pieces of extruded aluminum wedged under the tires, I decided to make something approaching regulation chocks. For the grand total of $7.75 I was able to make three chocks using 3/4" PVC pipe and fittings. I got the idea from a Kitplanes article by fellow 601XL builder Rick Lindstrom. Simple, but effective. Thanks, Rick.
$2.25 per wheel
Another advantage -- they are always snug against the tire