Southern Spain Trip Advice

Hello, I want to plan a trip to Spain between May 13 and May 26 or May 29 and June 10. I want to know what you guys think the best days to go would be and are most budget-friendly. I want to go for about 7 days and am thinking of these cities.

Málaga → Granada → Sevilla

With a possible day trip to Cordoba. Do you guys think this is a good idea, without it feeling rushed? Also, roughly how much would this cost (accommodation and food-wise), and what are the places that are a MUST to visit?

Any help is greatly appreciated. Planning is hard :)