There aren't any good houseplant nurseries in my area anymore, unless I count the overpriced and half-dead plants at the grocery stores. There are, however, a great number of places to buy houseplants online.
Amazon.com is a fun place to buy houseplants online. You can easily purchase plants, such as cactus, in bulk through Amazon.com. What's more, the price is unbeatable and, so far, the plants I have bought are in good to great condition.
You can also order some unusual and exotic houseplants that aren't found in local centers. These include fun plants like the venus fly trap and fig trees that can be grown indoors.
The trick to buying houseplants online is to do your research. Read reviews from people who bought the same plants. Before buying from an online nursery, do an online search for any complaints about the quality of the plants they ship out.
You can also check out Ebay and see what people are selling in the way of houseplants and bulk houseplants.