Slip Cases?

Hi again!
Personally, after spending good money for a top quality portfolio, I think $10 is an incredible value. I would happily pay significantly more than that for the protection and professionalism that a slip cover would provide.
I have a 12x12 portfolio. I found that record albums are about 12 1/4" x 12 1/4". I obtained a black slip cover meant to hold 6 or so records in a box set.

Hi, thanks for answering! I assume you mean a "slip case" (like the pic below) and not a dust jacket. Slip cases are really nice, and convenient for select uses. However they are also really expensive... upwards of $10 even when ordering in a reasonable bulk quantity. There is also the thickness and sizing issue, so we'd need to stock multiple sizes.

I think a great accessory product you could sell for hardcover books is slip cases.
They are difficult to find; usually custom.
Having a slip cover is great for interviews to protect the book from wear and the elements (obviously) and to prevent "perusal" before an actual interview or meeting.