Last one I sold I sold for $200.00 Usd, I did a little looking and there
going for $175.00 calibrated here https://www.valuetronics.com/Details.aspx?ProdID=6025, also on ebay. (111 Gbp)
Bear in mind this is the 1st generation and there was an 475A version

Bonus, your scope goes to 200Mhz and does have options so you
might get a little more.

Steve @ Apex Jr.