Normally, a decent retractable gear mechanism costs hardly more than fixed to keep going, but this changes fast if it gets abused i.e. filled with muck which grinds up the bearing surfaces.
If you take off, or taxi under the required substantial power, on a sandy surface, isn’t going to cover the whole plane, never mind the gear, with sand?
It may depend on how loose the sand is. My only experience of sand was at Calvi, Corsica, 2014, which was dreadful. The stuff was loose and ended up everywhere… Only MEPs were allowed to park on tarmac.
I took a Piper Turbo Arrow IV to Barra. The sand there was compact and wet and contamination was limited to the wheel wells, which I cleaned at the next destination using the friendly fire-man’s hose. I guess dry sand may be more flexible but less sticky…
Barra has standing salt water, which will spray onto airframe. Sollas has mainly firm, dry sand, and usually wet bits can be avoided. But near the shore the sand is dry and blowy.
