Where can I find the best Portuguese egg tart in Macau? How much does it usually cost?

The most famous egg tart in Macau should be the Cafe e Nata Margaret's, which is located at Gum Loi Building, Rua Almirante Costa Cabral, Macau. It is just down a little alley one block from the Hotel Lisboa
The other one is Lord Stow's Bakery, which has set several branches in Macau, one of which is located at Venetian.