Just bought Disney Sing it at Blockbuster, brand new in the box for £20 including the 2 mics. They still have the solus games for £12.98 and said they have Disney Sing-it HSM3 with the mics for £20.
The mic's and adapter go for £20+ on ebay with no software!
Online they are not showing stock but the guy in my local checked a few others and there were plenty around.
I forgot to check but it looked like the other consoles were similar prices.