A slot holds a 0.05 SOL deposit. It pays what pump.fun charges to create the coin at the open and the rest comes back to you. If nobody opens the coin within a day of its slot, it comes back whole.
Your coin's creator fee on pump.fun accrues to a till of its own. Half of it is yours, forty percent feeds the Kiln, ten runs the pad, and anyone may harvest it for you.