I nominate you, because it's your birthday money! Someone wanted you to spend it on you, so you should do that (also you're pretty awesome).

My essential item is cuticle oil - it's the only thing that keeps my nails and cuticles in good shape. I wash my hands compulsively, so my skin gets really dry - I'm not sure if this is ever a problem for you, but everyone gets hangnails or dry skin sometimes, right? Cuticle oil is the answer. My favorite one for at home is Solar Oil, it smells nice, and also helps cuticles heal really well. The first one I got (and also most convenient for travel) is E.L.F.'s cuticle oil pen. They both soak in quickly so I don't feel like I have to wash my oily fingers again after I use them!