I got quotes from two companies:

 

MSIG, (Japanese company) 2,000,000 Coverage - Premium 4,834.26

 

LMG (American company) 1,770,000 Coverage - Premium 1,799.74

 

There's a little difference in the Coverage amount, but a huge difference in the Premium price. Why is that?

Because one of them can smell a rip off job coming. Or they have had  this year a bad claims record and they bottom line needs padding.

You will have to compare the T&C, that is the only way to find out,  when the insurance company will pay what. Is theft included to what max, how about water,  personal accident protection at home, third party liability etc