Another option is to use 'skids'. I built a 8X12 frame building on 4X6 treated skids just in case I ever wanted to move it- I never planned to do that. Turns out it's been moved 5 times in about 20 years but that's another story. The skids offer a lot more surface area to hold the weight, and don't concentrate it in one spot like any pier will- all while leaving airspace underneath to stave off moisture and rot. Some places it went left it somewhat pitched, but that wasn't enough of an issue to matter to me- it was level enough for my purposes.