Here is a similar pump that I bought. You can catch them on sale for about $30 or look on Amazon or similar places and I am sure you will find one.
When done I put a very small amount of Olive oil or something similar in the pump to keep it lubricated. I always pump out about a gallon of water on the ground before i use it the next time.
https://www.harborfreight.com/12-vol...ump-63324.html