Most eBay and Amazon sellers lose money without knowing it. They guess the price, forget fees, ignore shipping. When the sale comes in — the profit is already gone. FlipCalc fixes this in 3 seconds. Enter sale price, cost and shipping. Instantly see: → Exact net profit after ALL platform fees → Real margin % and ROI → Break-even price → Whether the flip is worth it or not Pro version ($29 one-time) includes bulk calculator, what-if pricing for 8 price points simultaneously, history tracker.