How much is a new battery going to cost me?

I can’t find an exact price really anywhere and I’m becoming desperate lol. My battery hasn’t really worked for about a year now but I’m a working college student trying to move (again) and haven’t really had money to spare so I’ve just been using it plugged in and always charging.

Today though, it won’t turn on. It’s just showing the apple logo on the start up screen and I’ve tried everything so I guess new battery it is. Do I definitely need to go have it repaired at an Apple Store or does anyone else have recommendations for somewhere I could trust? That also is probably location based so I’m in the LA / Long Beach area if anyone knows of a place! Just don’t want to be screwed over. It’s a 2018 MacBook Air if that makes a difference too!