You wouldn't have to desolder the ROM, just use this: http://www.retrodev.com/transfer.html I hope you do it, I don't think one exists publicly yet.
i saw two in akihabara years ago one was at trader, complete in box, the second has no bow, in little shop, for 98000 yens !
Works quite well, as you can see from my pictures of the hackjob-for-a-cable posted here: http://www.op9.net/vg/index.php?dir=scdtranscable&img=7 I haven't tried it with my X'Eye yet.
this asian multimega system i saw my local gameshop in brunei sells newbox around 150 brunei dollar, thats about 100 us$ i think, still left three boxes last time i saw, didnt know its that rare :-D