Is a master's of science more valuable than a master's of commerce?

What I would say is that a science degree, assuming one of the hard sciences (i.e. physics, chemistry, math or really any that includes math requirements), is always valuable. What it signals to any potential employer is that you have the analytical chops to do most jobs.

You can always go to social science or humanities after a hard science degree, the opposite is not true. Commerce or business degrees are usually about proving just enough aptitude while keeping enough time to build relationships and early networks. They can also signal "I want to make money" which for employers is not a bad thing because it usually comes with work ethic to do so. The MBA tends to combine all those signals. Although the networking portion is probably only as valuable as the prestige of the program. 

You also need to keep in mind that a degree may be valuable and in alignment with your profile but not considered valuable in other's eyes. So here, you need to take a call considering your profile, preferences and future objectives.

If you think any of this is difficult to do by yourself, you should directly get in touch with Study Abroad Experts here. They will analyse your profile and will share the most suitable options for you. 

Let me know if this helps and if you need any more information from my end.