I bought my copy of GS 3 SOLO on ebay. I re-registered with TASCAM. All I needed was the original proof of purchase (Invoice) of the previous owner.
No problems at all.
I struggled quite a bit to get it running. I have Kontakt 1.5 in parallel. But GS 3 is far better IMHO, much more pristine sound.
It was hard to install and I need to start it twice before it makes a sound (Probably due to my old layla card). Remembers me of an old car that you have to kick before it starts. But the result is worth the kick.
You are offering a SOLO edition, you know .... the kind you get free here and there. I have a copy that came with a tascam us-122 interface, and the whole thing cost around $100. So buying your free copy for $100 doesn't really make sense ....