Bob grows corn. Last year she grew 2,000 pounds of corns in a year while using 250 square feet of land and 1 worker. This year she doubled her land to 500 square feet, doubled her workers to 2, and grew 4,500 pounds of corns. She sells her rare, organic corns for $50 a pound. She pays her a worker $25,000 a year and rents her land for $100 per square foot for a year. What was Bob's total cost last year and this year?