Leasing Contract

Question
Lois owned a shopping center. It consisted of a large store space leased to a famous supermarket and smaller store spaces for 10 other businesses. Tony dreamed of opening his own coffee house even though he had no business experience; he decided to rent one of these smaller spaces. Lois and Tony orally agreed that Tony would rent store space #7 for one year on these terms: (a) the term would begin on October 1; (b) rent was $5,000 per month; and (c) Tony could assign or sublease only if Lois consented.
On October 1, Tony opened “Tony’s Coffee” and paid rent for the first month. Throughout October the business attracted more customers each week; the weekly revenue totals were $500, $1,000, $2,000, and $3,000. Tony concluded that the business was doing so well that he could move it to a larger space in another shopping center across the street. Tony orally agreed to transfer “all of the rest of my lease” to his friend Amy, so that she could take occupancy on January 1. Amy planned to continue operating the coffee house and had five years of experience running an ice cream store in the past. But when Tony asked Lois for permission, she replied: “No way. You’re the one who is so successful. What does Amy know about coffee? And if you open a bigger store across the street, you’ll take customers away from my center!” Disappointed, Tony failed to pay the rent due on November 1 and never paid rent again.
Tony’s business continued to improve through November; the weekly revenue totals were $3,100, $3,250, $3,500, and $3,550. But on December 1, Lois’s staff erected the shopping center’s annual Christmas display, where visitors could get free hot chocolate. The display blocked the view of the coffee house from the road; it also occupied the 10 parking spaces closest to the coffee house. The display brought more customers to the center, but not to the coffee house. During the first 3 weeks in December, Tony’s business seemed to stagnate; the weekly revenue totals were $3,510, $3,470, and $3,530. Frustrated, Tony signed a five-year lease for a larger coffee house space in the shopping center across the street, with occupancy to begin on January 1. On December 24, Tony sent this email to Lois: “That Christmas display is killing my business! Get rid of it. Tony.”
Lois never responded, so on December 31 Tony started moving his chairs, tables, coffee machines, and other equipment and inventory to his new location. Enraged that Tony was moving, Lois waited until he left that evening and used her key to enter store space #7. She moved all of Tony’s remaining equipment and inventory to the public sidewalk, and changed the door locks. Lois then made diligent efforts for 9 months to mitigate her damages by trying to re-rent the space, but without success. Lois now plans to sue Tony for $55,000 in unpaid rent.
How much rent does Tony owe to Lois, if any? Why?