All said and done, I have no issue disclosing the price... providing I can still remember it, and in this case I found it in my purchase log on the Saleroom website.
It was 1500 GBP (hammer price) + charges, and I got it from Bonhams, on 27 November 2019.
Now I have a question of my own: why would be rude to ask about the price?!
I noticed on multiple occasions that asking about the price of an item was somehow considered "tabu" subject but I do not understand why?!