How loaded is she? A grand piano, one suitable for concerts goes in excess of $100.000 as new, this looks somewhat smaller, a 'parlor grand', but at that size a new one would still be +$50.000. Perhaps she found a great deal on a used one? Or leased it in which case she may have gotten away with just a grand or less. The manga did say she went 'shopping' but the last one would be the most(or only) sane option here...