Surprisingly, yep the 11-50 models aren't anywhere near the stratospheric prices of the SS80 and SS100s. Considering George Brough's 1939 SS100 sold this year for £253,500, this seems like an absolute bargain!
Here's a previous 11-50 sale
https://www.bonhams.com/auctions/13243/lot/301/
The condition of the one here in Australia and the addition of the sidecar seems to pu
t the estimate in the correct ballpark. I'd still love to see it go for over $100K.