@ stush
I know what you mean about buying them all.
Its a rush isn't it when you just chance upon something you have been looking for ages at a bargain price . I was getting into hybrid aloes, but a lot of them are hard to find here in the UK. Especially the Karen Zimmerman hybrids. Then one day in my local garden centre , there they are... a bunch of aloes that look very close to a Zimmerman cultivar known as 'DZ'. They are marked up as 'franco /lime fizz' . So i buy two there and then and go back and get another a few days later. Anyway long story short is that its seems the two plants are one and the same. There is a US collectors who has bought both and grown them 'side by side' and they are the same plant. His theory is that someone in Europe must of tissue cultured dz . Shortly after similar or the same plant started popping up all over the place her in the UK. So I think the theory sounds about right.
So as you say wait it out for long enough and hopefully what you are looking for can often pop up.
Steve