If you are not in too much of a hurry, take a look at the chargers offered by EMW. They are bringing a low-cost charger to the market that has up to a 60 amp, 15kW capacity that is made for the future.
You will note on the website that they are holding off on further orders until they clear orders. I would imagine that your availability might not be until November or December. You will also note that you have to order the cables separately. This means that you might end up spending another $200 for the installed cables. The price of the assembled unit is $240, so your end price for a small, powerful portable unit will be less than $450. (Check out the shipping cost though. It might be another $50 by now. California shipping is by far the cheapest.)
http://www.emotorwerks.com/products/onl ... ng-station
My cost was about $420 including shipping because I got in on the ground floor. But the unit is still the lowest cost 30 amp+ L2 unit you can find. And it is fairly small. I expect to get my charging box early next month. They have had their delays, and we don't know for sure that the unit will be as great as they say. So if you don't want to risk it, or wait for others to test it, this might not be for you.