nope
1) ishibashi uses EMS (a japan post service if i m not mistaken) , no $10 singpost charge. i have heard it singpost would charge you an Additional $5 if delivered to your doorstep. they would call you upon delivery and you can
a) pick it up at the nearest post office or
b) get them to drop it off at your place
2) any charges for ishibashi. there are predominantly 2 charges
a) shipping charge. the shipping charge would be yen 10.000 which is approximately SGD$155 at current exchange rates.it WOULD NOT be cheaper to ship via VPOST as you have to wait longer , pay both internal japan taxes, and have insurance on your shipping up to $400, whereas EMS is within 7 days, air freight immediatly from ishibashi warehouses and your guitar would be fully insured and returnablefor an instant refund on the spot if there were to be any defect
b) 5% GST would be made payable to the singapore government upon collection of the guitar at singpost. i have heard 2 conflicting reports of payment methods. one says you must pay when the goods arrive, and the other says you must pay the GST in FULL within the period of 6 months after reciving the goods.