I really like lego, how do I ask my grandparents for my own? [I Play With Toys]

I was never allowed toys growing up, but after I moved in with my grandparents I’ve been playing with my cousins toys a lot. I like legos the most, I like building it.
My cousin doesn’t always let me play, n I pretend I don’t mind, but I honestly really want my own toys, or at least some lego.

I know it’s expensive, n I don’t really know how to ask my grandparents for it. Any suggestions?