Google.com search is your friend:

https://www.google.com/search?q=buy+Jacaranda+tree&aq=f&oq=buy+Jacaranda+tree&aqs=chrome.0.57j0l3j61l2.5982&sourceid=chrome&ie=UTF-8

Here is a link that might be useful: Jacaranda trees for sale

I saw some at zone 9 tropicals (online) a gallon for 17.99.
I have not bought trees from them but I have purchased several vines from them over the years and they send the nicest vines that are on a trellis and healthy.

I have seen them from time to time sold as small seedlings from a vendor on ebay wellspring nursery. I think they have a website as well now that sells plants. They were a few dollars last time I saw them. I have no clue how long it would take to flower from a seedling though.

Here is a link that might be useful: zone 9 tropicals

I have been growing Jacaranda trees in my yard for the last 18 months or so, and have lots to get rid of. Biggest ones are in 15 gallon pots and over 8ft. tall. Send me an email and I can reply with pictures. Live in West Melbourne.

This post was edited by Jacarandamelbourne on Wed, Sep 10, 14 at 9:35