Many people think the best idea is to initially press up 1000 units (CD, vinyl etc) and sell them all. Many people end up with 900 plus units stored under their bed till they decide to give them out for free. It’s not as easy to sell units as many people think.
Unless you’ve built up a big name for yourself and have a proven track record of selling high amounts of CDs I suggest you start by pressing up a test batch of your new CD or vinyl, a good amount being 100. Now you may think you can do much more then this, but if you can what’s the harm in pressing up 100 at first? Then if they sell as fast and well as you expected, press up another 100 or 1000 (Dependent on how well the first batch sold) and try to sell those too. It’s just a way of being safe, no one wants to splash out money and not be able to recoup it.