Two ways of looking at that course...
Yes, it can lessen the chance of a bargain because more have seen it, but it could go the other way with lots of potential bidders thinking they won't bother for the same reason.
But, for the collector, the price is sometimes of lesser importance than the knowledge its for sale and the choice on whether to make a bid for acquisition.
The price will be what it is.
It can also have the effect of keeping the value of these items up, which is good is you're already in possession of the same or similar.
I for one have thought Webley Seniors have been under-valued for years, they have a quality than can only be truly appreciated once in the hand.