contract act sec 27

If the contract is signed then of course it is not only valid but binding, Company is supplieing you products at lower price conditionally.

Yes ,contract is perfectly valid and not against any law or public policy, buyer is bound  by the terms of contract.

Such a condition restraining sale cannot be imposed for the basic reason that the goods are being purchased for being sold. When the buyer and the seller mutually agree to but the goods at a particulare price and the seller undertakes to sell it at a particular price, how can a condition restraining sale be imposed. Query is misconceived.