A lot of ‘prime days’ are simply discounting unpopular or slow moving stock, so it’s daft to just browse in the hope of finding a random bargain (most of the time).
As the OP wants something specific then find a few varients of what you want, add them to your wishlist/save for later, or whatever it’s called.., and check them again on deal day/week.
I actually got a really good deal on a silent night matress… but as always.. always look for the same thing/same model elsewhere to compare prices… just because amazon have reduced something from £200 to £100, doesn’t mean it sells for more than about about £100 all year round via other retailers.