I have both PAL and US Shemue and seeing that is JPN release I'd say it will probably worth less than the other two...
Could you post a few more pictures, PhantasyStar? The one you posted looks more like the Japanese box then a system.
The inside is like a regular dreamcast, but it's a Shenmue Box for the Dreamcast system. Whoops, maybe I should change the name to "Shenmue Dreamcast Box"
Maybe ask idrepublix about it? Sadly, he got in a bad car accident recently, so it'll be a while until you can do that. :smt022
If I had to guess, I dare say it wouldn't be that much. Since it is just a regular japanese dreamcast with the japanese version of shenmue in a semi-rare box, i'm guessing around $50-100 US on a good day on ebay.
http://www.dreamcasthistory.com/dreamcasting/viewtopic.php?t=1847 :smt009 I'll go post it in O/T so anybody who has trades or something going on with him can sort that out and knows what is going on. Sad... :-(