There are several things to consider when buying Bromeliads on ebay, the most important thing is making sure that you know exactly what you are getting.
The ideal situation is where the plant is an established plant and is clearly photographed, with mature dimensions stated and the seller is situated locally so that you can collect the plant.
This means that the plant is actively growing and unlikely to die, and you can discuss your purchase with the seller when you collect it.
Far too many sellers simply sell fresh cut "pups" with a photo of a mature plant, the photo may or may not be a photo of the mother plant, it may even be a photo "acquired" from the internet.
Even if there is a photo of the actual mother plant, there is absolutely no guarantee that the offset will grow to resemble the mother.
Bromeliads have a habit of throwing offsets that are inferior (or occasionally superior) to the mother plant.
Both of these photos are of pups removed from the same mother plant, they clearly show the vast difference between pups of the same parent.
Both are Neoregelia Fosperior Perfection, and both could have been sold as Neoregelia Fosperior Perfection - but I know which one I would like to buy :-)
Unseen, unrooted and potentially immature offsets are a gamble as you do not know exactly what you are getting, and there is a chance that the pup will die and your money will be wasted.
Unless you are a keen collector who is after a specific plant, it is best to avoid buying pups.
There is one exception to this though, several sellers list a "job lot" of assorted pups - if you can get these for a cheap price then it may be worth the wait for the pups to mature.
Buying fresh cut pups means that you can expect to have to wait many months for them to become established.
This may be fine if you have a shade house where they can remain undisturbed until large enough, but if you want an instant effect - pups are best avoided.
Strangely, the price that pups sell for is pretty much the same as what you can get an established plant for.
You would expect to pay a little extra postage for an established plant as they are larger and require more preparation (than a pup) prior to postage.
Don't rush into your Bromeliad purchase, new plants are always being listed.
There is little worse than getting caught in a bidding war, paying way too much and then seeing a similar plant sell the next week for a fraction of the price.
Buy established plants to avoid disappointment, there are plenty of growers selling established plants but unfortunately there are more people with the "snip and sell" attitude.
You don't always get what you pay for, but if you pay attention there is a good chance that you will.
Finally, and at the risk of repeating myself - always try to buy locally, you get to see how the plants will look when mature and you get to talk about growing Bromeliads with the seller.
Hopefully this "guide" with help you avoid disappointment.