This is now an old machine, which you can no longer purchase new, but to find a used one at a low price could be a bargain.
Positive Product Points
The Buon Caffe 330 is a good machine. It makes great espressos and Americanos with a rich crema. It's easy to use and heats up quickly (less than five minutes).
Negative Product Points
The biggest downside is that the company who made these for Starbucks (Estro) went out of business. It's not easy to find parts for it, but I've heard you can buy parts that are made for the Krups 964 and it will work for the Buon Caffe.
The Buon Caffe 330 is easy to use and would probably make a good entry-level machine. I bought it as an entry into the world of espresso and have been quite happy with it (especially after buying a conical grinder). It makes great espresso shots and is very easy to learn. It doesn't seem to produce a lot of steam, however. I can steam milk, but it takes a good minute or so to bring 8 ounces to the proper temperature and never has good microfoam (but maybe that's due to my lack of experience).
I have not had to buy any gaskets or other parts for it, but it won't be easy when I do. The company who produced the machine went out of business so parts are hard to come by. However, I hear that the group gaskets for the Krups 964 will work for this machine. (See Micah Shields' review)
The Buon Caffe is a nice-looking and solid machine. It's made from a composite metal that is grey in color and has black plastic trim. It is small enough to fit on just about any kitchen counter and heavy enough to dampen the noise from vibration.
I bought the machine through Ebay. It was used and did not come with the single shot basket. Overall, I was pleased with the purchase.