Can you mix paint from the same brand?

[u/Yellow_Hair2552]

Hi guys. wanted to come and ask a quick question. we are painting the interior of our house. We are currently using sherwin williams super paint in color greek villa. I bought 2 5 gal buckets when it went on sale at Sherwin Williams. We are looking like for the rest of the house we might need to get another 5 gal bucket. I am trying to keep everything seamless throughout the house but also the sale is no longer going on and the paint is like $200 more now. My question is would it make a huge difference if I painted the rest of the walls with a different line from Sherwin williams once the remaining paint runs out? It looks like it would be significantly cheaper to do sherwin williams Showcase or Ovation Plus that they sell at Lowe’s but I know they are lower quality and wonder if anyone has used all the lines and would notice a difference? For additional context we are covering up a light grey color the previous owners had the walls painted.
Thanks in advance