blue chip
(adj.)
a type of stock highly valuesd for its long record of steady or long term earnings; also a valuable property
EXAMPLE:
The investor bought 100 shares of stock in a blue chip company.

 bone of contention
(noun)
a disagreement, dispute, or argument about something; a strong difference of opinion; a conflict
EXAMPLE:
A bone of contention was the division of powers between the national and provincial governments.

brand x
a marketing classification describing a product that doesn’t have a highly visible or recognized name like a well-known product or "brand name"
EXAMPLE:
It was decided to buy brand x because it was less expensive.