Forum:Help with understanding the sphinxes

With Andro Sphinx and Sphinx Teleia their descriptions say that i can pay 500 life points to normal summon them whilst 'Pyramid of Light' is on the field, does that mean i can only pay 500 life points to summon them without tributing 2/3 monsters (whichever it is) or must i tribute 2/3 monsters and pay 500 life points while 'PoL' (Pyramid of Light) is on the field?