i dun think ayu will be selling lower than 500K at least. She should have at least 500K hardcore fans in Japan (judging by the fact that most of her albums sold over 500K on the first week). 700K shouldn't be a problem as well.. hopefully it can get over 800K. Of course, a million seller would be superior
so my guess... 500K - 750K overall..
If JEWEL is splendid and two new songs are excellent (well.. let's say there should be 8 songs in total for a mini-album), then the range could shift to 700K to 900K..