I don't think you should make a decision just based on the package. Because it is a startup, there can be various things to consider. You might have to work more than you work in your MNC, you might have more pressure than in your current job. If the startup goes in loss, they might lay you off. These are some things you have to think about and decide whether you are ready to take these risks. The good thing about working in a startup is that you are exposed to the whole product and not just to a part of it. You will get to learn more. Consider all these parameters and then decide whether you should switch or not. Don't let a better package be the only reason.