The best time to visit Lisbon is either from March to May or September to October, because the weather is still warm, hotel rates are cheaper and there are fewer crowds than in summer. In those seasons, you might also be able to squeeze in a few beach days.
Is it expensive to eat out in Portugal?
According to the website Numbeo.com, a three-course meal for two people in an average restaurant is currently around 30€. However, in the typical Portuguese restaurants, the "prato do dia" is available for around 7.50€ for a main course, drink and a dessert.