cheap camping around sacramento and yosemite.

[preston uk]

 I'm finishing my cross America route at Sacramento and hope to have time for a trip down to Yosemite .

Does anyone know of cheap / primitive but reasonable quality camping around sacramento? I have to call in  at the airport to clarify an issue with flying with my bike back to the UK.
I've checked Sacwest RV park and it gets terrible reviews. Does anyone know if Beals Point on Folsom lake does hiker /biker sites ? They are quoting about $28 for camping - a bit high.

Can anyone recommend cheap camping and a route from Sacramento to Yosemite ?
Thanks in anticipation.

[tortoise]

Beal's point is pretty nice. It's not fancy but it's right on the lake with restrooms and water.