It depends on what the margin is for the store on each unit. If the cost to the store is say $300, the store makes $3000 MORE profit at the $350 price than before.
What do you mean the store made more profit at $350? At $350, the store made $5,000 profit [$100*(350-300)] while if the price had been left at $400 immediately prior to the spike in sales they could have realized a $10,000 profit [$100*(400-300)]. >:*3