I got them new through Amazon.com
I got the pair for $61.30 plus $11.99 shipping and had them delivered to my office. It was painless.
On my maiden voyage, while I was leveling the trailer there was a dip behind one of the trailer tires. The trailer slid back about 3 feet and struck a wood pole. No damage was done but it was scary!
These are great I put them in nice and snug and the trailer does not move!
I also suggest to get some tall piece's of blocks and place them under the stabilizers. The less the stabilizers have to open up the better the support and stability. There is a thread somewhere here on this. I don't have them but am looking for the blocks myself.
I highly recommend the BAL Scissor Jacks, you won't be sorry!
There is also another thread on here about the up and down motion due to the trailer suspension, they have some great ideas to minimize that also.
Good luck, if you purchase them let me know how you like them.