Due to the extremely bad memory interface on the Cyberstorm boards it might end up being the same speed as an A3640 or even slower.
Please note that the bad memory interface only applies to the Cyberstorm 060->Amiga Ram or 040->Amiga Ram. The PPC->Amiga Ram interface is much faster.
I always thought they crippled the speed of their 040/060 cpus on purpose to make the PPC seem more faster than an 060 than it really is. Many people were fooled.
If you ask the same price as a good A3640 + 30 Euros. That would seem like a fair price to me.
Don't think of that as to low a price. Think of it as being a heck of a lot more than 0, which is what you would get if the card was dead.
No I will not pay that price for it.

After my experience of owning an A3640, I refuse to buy any accellerator without onboard ram.