No. Buying an email list is generally not a very good idea. When you purchase an email list, you will be sending your emails to people who did not give you permission to message them. In other words, you will be spamming. Another reason why buying an email list is not a good idea is that the people in that list do not care about you or what you have to offer. Therefore, there is a very low chance that you will actually be able to convert these people into paying customers. The best approach is to build your own email list of people who have actually shown interest in what you have to offer and are therefore more likely to buy.