No — but unusually cheap wire is almost always worse.
Price differences usually come from three places: the insulation grade (HFFR costs more than FR), the amount and purity of copper, and brand positioning. The first two are real engineering differences; the third is not.
The way to tell them apart is conductor resistance in Ω/km. Two wires both marked 2.5 sq mm should both meet the IS 694 maximum. A wire that misses it has less copper than its marking implies — the most common way cost is quietly removed.
Compare within the same grade, check the resistance figure, and confirm the certification. Then price is a fair comparison.
APAR publishes conductor resistance for every size — see any house wire specification.