I live in an area that is ideal for orchids; so thus, we have a few really good orchid stores.
However. I saw many beautiful plants on Ebay.
Many. I began to drool. I had to have them.
I'm absolutely hooked on sedireas and neos of every shape and size.
My problem is this. You're taking a crap shoot. For whatever reason I have had 50/50 with the plants coming with pests. You can't exactly inspect the plant. I've bought a lot of Neo Falcatas online, from the same source, and some had a type of mite. I bought a few draculas which were infested as well with several pests. But I just got the most BEAUTIFUL Dendrobium spectabile....huge, healthy...a real keeper. Perfect.
I had contacted these sellers and they all happily replaced my plants or refunded. Sadly, one was replaced with the same pests...go figure. ;/ All my orchids are kept indoors so I have to go to natural means of pest control with a little one in the house. Not always 100% effective.
I haven't ordered anywhere else, this is just my experience from Ebay. There are A LOT of great sellers with wonderful, perfect stock. You just have to keep those things in mind.