I spotted this at JB Hi Fi in Forest Hill (Melbourne) so I am unsure if it is stocked in other outlets. Knocked down from $59, which seems a bit extreme, and it is listed at $49 on Acer's own website.
I bought one about a year ago for about $12, which I thought was pretty cheap. It is a tight fit on my A500 but it gives access to all the buttons, but not to the MicroSD card slot, which is a bit frustrating.
It might fit other 10-inch tablets, but I have no experience with those, so it might be pot luck. On the other hand, it's only a buck!
OP, any link to Jbhifi or a photo upload?