I have friends and family from San Diego to Sana Barbra. They have said they have not found any good quality extract source out there. From a commercial point of view you are not goin to. Quality flower is worth more as a flower. Trim, popcorn, lower quality bud is worth more as an extract.
Making your own may be an option. There are several simple, inexpensive extraction methods. That way you know what base plant and quality was used.