You can try purchasing Antminer L3+. It is the most efficient litcoin miner untill now. It can give you a good profit of maybe 20$-22$ each day. It's pricing on the official site of bitmain would be around 0.7 btc i guess. You can try purchasing it. It is out of stock currently but you can try contacting BITMAIN for the next sale and you can stay update to the site.