In the Name of Allah, the Most Gracious, the Most Merciful.
As-salāmu ‘alaykum wa-rahmatullāhi wa-barakātuh.
Bargaining is allowed in Islam. If a purchaser wishes to bargain with the seller on an item, he may do so. The seller has the right to either decrease the price or maintain his price. If the seller and the purchaser mutually agree at a price, the transaction is valid.
However, as Muslims it is essential we be honest and fear Allah Ta’ala in our dealings, and be averse to all forms of deception and dishonesty. As for the seller, he should consider the wellbeing of the customers as well and not be driven by greed only. The buyer should also consider the welfare of the seller and his right to make a reasonable profit.
And Allah Ta’āla Knows Best
Mufti Arshad Ali
 (بدائع الصنائع في ترتيب الشرائع، ج5 ص133، دار الكتب العلمية)