Affordable quality horse riding lessons?

So my 7 year old had an amazing week at Kenilworth Stables Horse Camp this summer.  We would LOVE to continue but the cost and frequency of lesson requirements are not at all in line with what we can afford.  My gut tells me that a quality riding program that takes good care of its horses is just going to be crazy expensive.  But hoping I'm wrong.  I checked around online and checked if our local park district (Berkeley, Alameda County, East Bay Parks...) offered lessons and they do not.  My daughter would love to continue.  Any advice?  We can go as far as the Redwood Rd area of Oakland or north to Sobrante but of course would love something close too.  I know!  So much to ask...