because i tend to tailor each one to the book, as far as colors and lining materials go, i am spending more than you have to.
which means i buy a brand new small package of Lineco bookcloth, for example, for each one, rather than a much cheaper roll of book cloth. but my boxes are all different colors. a single roll of cloth would be much cheaper, but they'd all be in one color. meh.
so:
-assuming acid free board (I use bristol board, which is more expensive but easier to work), a sheet is $10-20. you can do two books or more from one larger sheet
-The book cloth runs maybe $20+ depending on size of the book. Lineco's is unfortunately small, 17"x19", and i don't always have enough for both trays and the outer case. which is why i use...
-marbled paper lining for the lower tray. it is about $30 including shipping for a full sheet. you can probably get two lower trays (the tray that holds the book) per sheet.
-PVA glue goes quickly. it's probably $7 for a bottle that you will use up on one or two boxes. I now buy the larger $40+ bottle. you can stretch it with methyl-cellulose too. it actually is sorta required anyway, because the PVA is thick. the methyl-cellulose will thin it and make it easier to use.
-olfa cutters, blades, brushes, etc. are required too. I use a couple small plastic triangles (drafting equipment) to assure 45-degree and 90-degree angles.
without buying in bulk then, if you are just buying to do one or two books at a time, it'd say it will cost you $100 to do something really nice and well-considered. You could probably get by for half that though, if you had to.
the time is more about drying time than execution, but i probably put in 10 hours between design and execution, but that's because each so far is a unique one. i also add the complication of a sliding tray (for the really rare and potentially delicate leather bindings). you don't need a tray for most books, it's just most of my books need them. the "Broom of the System" I am doing now in in a Brodart cover, and so I am simply lining the trays with simple felt (no sliding tray).
with everything at hand and experience, you could bang them out (excluding drying time) in a couple hours.