Make a list of what you have. Compare to either forums or online and make a judgement call on how much you are willing to part. I know and most of the community knows when can’t put a price on our time and care for these animals. Ultimately it will be your decision on price. Livestock and...
Not sure you need to get that elaborate, just an air stone while you mix. I have a pump, heater and air stone connected by a power strip. When I do a water change, I let it run for a few minutes and start adding it to the tank.