Not knowing your location, I cannot recommend a regular nursery. Lowes and Home Depot often carry them, and you can check online for availability. It isn't really the optimal time of year they offer them, but I live in Southern CA where it does not get very cold. A quick check in my area showed them available at Lowes for pick-up ($8.50), and for delivery from Home Depot (a rather horrifying price of $22.40 for a 3" pot).

Thank you Gyr! I just ordered it from Lowes and it is being delivered from Hirt’s Nursery for $16 total! I think he will have to feed it hamburger because I never see any insects when I visit!