Why the 3th party insurance prices has so much different?

linxd SG

I've been insured my motorcycle through Mitsui Sumitomo,
through their agency Guan Hoe Cheong Trading Co. (¹a¹),
in the past 3 years, I always paid about S$132-S$136 for
my third party coverage (125CC).
Every year, Guan Hoe Cheong Trading Co. will send me
a letter to remind me renewal , and also tell me that if
I renew with them, will get 10% discount blah blah...
then I find out the prices they've charge is always the
same, they said the S$132-136 is always discount price.

This year, I happen to change the address, did not
get their renewal letter, then I try NTUC income, they
only charge me S$91.

Why the prices are such different? is it because
Mitsui Sumitomo prices are higher than NTUC income,
or the agent cheat my money?
or the coverage is different?

Mitsui Sumitomo and Guan Hoe Cheong Trading Co
has never send me their policy terms and conditions,
so I really do not know their coverage. although I've
requested several times before

hohosaint SG

You can be sure that they'd taken your NCD varies from 5%~15%... Basically, NCD varies from 1st to 3rd years to reach maximum 15% No Accident Rebate. Most of the black motorshop'll not let you know the NCD status of yours so as when exipry date's closing, they'll nofity you of the issue and at the meanwhile, your NCD'll be taken away and dropped into their pocket.

Just be informed of this said issue. All insurance companies should be the same charges unless the vehicle you wanted to insure's prohibited by existing company or thereafter.