Nope, no idea about prices yet. It's up to the manufacturer/management/label etc. I have no clue how much those things generally cost..?
I can't recall precisely, but necklaces could be around $10, buckle - $20-25, flask - I'd say anything around $30-50 (something like that was during CoB concert, they didn't have a flask, or did I miss it, since I go to the merch table after the set). But those are more my expectations, as well as general prices on the market as far as I know.
I gona get a flask.