Sherlock,
You are missing the point and excluding some costs. If you wholesale a home to a rehabber in your market and they pay 70% ARV from you they still have to pay holding costs (which are probably high where you are), they have a 5-10% fudge factor built in, closing costs, property taxes, utilities, permits, debt payments, not to mention taxes, which are taxed at very high rates depending on how they have their business set up. So that 30% potential profit is really 15-25% BEFORE taxes. This also assumes they can sell it for what they thought was the ARV. In Cali and other high dollar areas, values are still dropping it appears to me and were so over inflated to begin with they have farther to fall than many areas, such as compared to mine in the Midwest. So in the course of the rehab, the ARV has probably dropped some in that time. Plus so many people have a harder time selling retail now due to harder financing requirements, bigger down payments, etc. You are burning a lot of cash holding a property if it takes longer to sell than you thought it would. I am not an expert on Cali or other high dollar areas but if I was doing a rehab there, I think you can see why it pays to be conservative in all your estimates to make sure you are not upside down on a rehab when finished.
I guess my point is that I would be buying as cheap as possible. I would be more comfortable with lower than 70% if I was buying and rehabbing there. Again, I don't live there so I am hesitant to answer at all but the above is how I would look at it. Talk to someone who knows your market better than I. The easy rehabbing days seem over. I would be pretty conservative in my estimates of value, costs, etc. Can you still make money? Of course. But things are much tougher than a few years ago.
If I was a rehabber in that environment, I think I would give the wholesaler, less money up front in return for a cut of my profits in the end, just to keep my costs as low as possible. Not sure they would go for it but you have to get creative in this business.
I hope that helps some.
Mike C