Most - nearly all - philatelists are looking for things which fit on an album page. Today, an album page means a sheet of A4. Dealers can't sell items which will not fit on an A4 sheet - unless the collector can see a way to fold or cut the item to fit the page.
This is a bad situation to be in. Imagine. Someone offers you the Mona Lisa and you say, No Thanks, IKEA does not do a frame that size. Or worse: Yes, please, I think I can cut it to fit ...
Covers and sheets (Ganzbogen)should never, ever, be folded, trimmed or cut to fit. It is the frame that needs to be changed!
Many large format items get damaged because dealers don't have protective holders to put them in.
A well-preserved large format item can be a very attractive thing indeed. I have always liked the above cover. I think it's visually very appealing. It is made from (unfinished?) Court stationery. The address to the Justice of the Peace Court in Kamenets Podolsk is written in large letters across the front. The Registration cachet of BALIN Nr 165 is also in manuscript. The two 25 kopeck stamps are overprinted with Podillia XVIa (Bulat 2129, $30 each)and neatly cancelled BALIN POD in violet. On the back, there is a receiver cancel of KAMENTEZ POD "c" 22 4 19
This item is still in my stock for just one reason: it's too big. This implies we have a very strange approach to collecting!