They're easy to find. I've seen them at Armstrong Nursery and even Home Depot.

I got mine at a cactus nursery in Reseda, it's on Saticoy St. only open on the weekends, but I forgot the name of the place.

Never seen them at the Depot or Armstrong, not the purple ones. Any nurseries in the South Bay have the Most?

I would think any local nursery near you that has a decent collection of cactus will have a selection of santa rita. I purchased mine from my local nursery though I am a bit Inland. One caution. The Santa Rita, as all Opuntia do, grows large normal spines but also tiny spines called glochidia. These glochidia are the ones to look out for. They are almost hair like but will make your life miserable if you accidently brush up against the plant. I handle mine with barbeque tongs to prevent accidental perforation.

Any nursery will be happy to order one for you. Monrovia grows them and I'm sure the other wholesalers grow them too. You can also order from Monrovia for pick up:

Santa Rita Prickly Pear

They also color up better in the cold. When it's hot, they don't look as purple.

Mine is the opposite jxbrown. It is almost florescent in the summer but just a muted lavender right now.

California Cactus Center in Pasadena has it too.

Fireball... My wife found out about glochidia the really hard way. She got poked and thought it was a poke from one of the spines and instinctively put her finger in her mouth. Bad move. Had them irritating her tongue for almost a week.

I finally found them at a local Lowes. It was definitely not purple. Will my zone be too temperate for the purple color ? 10b Sunset 24