The reason I took the trip over there in the first place was for a miracle fruit plant. JRN is the only local source I know of for miracle fruit. They're not cheap ($45), but they're much cheaper than mail order plants when you add in the cost of shipping.
Also, while I was talking to the owner I asked if she had any jaboticaba trees. She said she did, and led me down several twisting and turning aisles to the back of the lot. There she pulled out two spindly, unlabeled specimens. I wasn't sure these plants were really jaboticabas, as I don't have any personal experience with them. However, the price was right, so I decided to risk it and bought one.
I posted some pictures of it on the TXRareFruit Growers forum. Hopefully they'll be able to tell me if I what I bought is in fact a jaboticaba, or if I got scammed. I'll be posting separate blogs about the miracle fruit and the jaboticaba later.
The TXRareFruitGrowers Club was able to confirm that what I purchased was a jaboticaba. I may have to go back and get the second one for cross-pollination.