I have seen them on ebay searching the words "cake stand"
I got them from efavormart on line. You can order the individual size plates & pillars that you need, or order a pre-arranged set with different sized plates. They look nice but stay away from the really tall pillars - they are pretty unstable even with a small cake on them.
Thank you I will check out their site.
I think that stand is called Crystal Splendor from Wedding Fads.com. I have a set. HTH
I purchased this set for a 100th Birthday celebration:
Be sure they are LEVEL at the venue. Bring a level with you and check them before placing the cake. (I didn't. Here's a link to the photo. The orange cake is just a little cattywampus.)
I agree that you should not go higher than 15" unless you weight the bottom of the stand. Even a teensie-tiny bump will knock it over.
I LOVE these puppies! They separate and store flat and look stunning.
(FYI: I've seen a LOT of bad reviews about EFavormart.)
Here's the link for the different sets of cascading stands:
efavormart stands are terrible. The ones you want are called "Crystal Spendor" as the pp stated. Search that and you will find several vendors.
Just a bit of info: when using this type of cake stands, make sure that with the poles that are 15" or 20" place only 5" to 6" size cakes to prevent tipping over. Also, these cakes should not be taller than 4 inches high, better yet 3".