Please show calculation steps to the following problem:
Central Ski and Cycle purchased 50 pairs of ski boots for $350 per pair less 30% and 10%. The regular rate of markup on selling price of the boots is 50%. The store's overhead is 25% of the selling price. During a January clearance sale, the price was reduced to $325 per pair. What is the rate of markdown and what was the profit or loss on each pair of boots at the sale price? Answer to the nearest cent.