Sell Antminers or not?

Good day! I have 4 Antminers 104 ths. Not sure whether to sell or not? The math is following: I bought them for 1500$ each last June. Now they cost 500$ on the market. Today I've got my mining check: cost of mining monthly: 270$, mined BTC monthly: 340$. The pros of keeping miners: getting 70$ of net income monthly; maybe price will pump back in bullrun to 1300$. The pros of selling: getting 2000$ ready to invest in BTC in case it pumps anytime soon, mitigating risks of Antminers losing their cost even more

Edit: check is for monthly use Edit 2: thanks for all ideas and replies! Have a great day :)