I tried dragon fruit last july, and though I wasn't impressed with the white fleshed fruit, I really enjoyed the red fleshed one (Hylocereus costaricensis). I sowed a bunch of the seeds and right now I have about 50 tiny dragon fruit cacti. I have 30 red fleshed seedlings and ten white fleshed seedlings that I want to give away (they're so crammed together none can grow any more!) They're small enough that I think they can go in an envelope if you supply a little vial or tic tac container. I'm pretty sure it wouldn't weigh more than an ounce but if you want more than one you should add extra postage.
These are great outdoor plants in zone 9-11, since they can take huge amounts of water and grow really fast (you can also grow them indoors if they have something to climb on).
Uprooted they'll look like this:
If you don't supply a little plastic container or something like it, I'll still try to ship one, but I have no idea if it'll make it. Just pm me the type you want and I'll give you my address. Totally not required, but I'd also appreciate any common cp seeds (just out of the goodness of your heart.)
---------- Post added at 06:05 PM ---------- Previous post was at 05:08 PM ----------
Oh, and also, the seedlings range from 2 inches to 1 mm. I'll send the biggest that can fit in your SASE, so any hard plastic container will do if you just want whatever. You don't need any fancy packaging for this, these guys can survive in a cramped space for a few days or even weeks. As seedlings these can be grown on a windowsill in the winter, outside in full sun in the summer. They're pretty hardy, I have a larger plant about 2 feet high I left in a dark corner all winter, and when I put it outside it started growing again.
Handy links for when you receive the plants: