Long story short, bought MU when it was at 64 dollars. I have 1.7 shares so it's now about 1600 bucks. Selling a bit to make a profit is going to be like 200 bucks tops, so feels like it isn't worth even bothering.
I guess this is also a general question of, "at what point do you sell?". I'm young, so not really in a rush, and I'd just reinvest it into something else anyway, like MSFT or VOO.
I'm at a point now where I make enough money that it seems like a good idea to start throwing hundreds or thousands at stocks, rather than 50 here and there.
edit: sold it all and put it into SPCE