BPI Credit Card payment

Hello!

Balak ko pong bumili ng appliance using my tita's BPI CC. First time ko lang po kasi.

1) Which is better po na payment sa store, straight (not sure with my term) po ba or installment? Mas mahal lang po ng ₱700 kapag installment. 2) Kapag po ba straight, yung bayad po ba sa CC, pwedeng installment? May interest po ba kapag ganun? 3) Kapag po ba installment, installment din sa CC? May interest din po ba?

Thank youuu!