A manufacturer offers an inventor the choice of two contracts for the exclusive right to manufacture and market the inventor's patented design. Plan 1 calls for an immediate single payment of $51,170. Plan 2 calls for an annual payment of $1,617 plus a royalty of $4.32 for each unit sold. The remaining life of the patent is 10 years. MARR is 10% per year. What must be the uniform annual sales to make Plan 1 and Plan 2 equally attractive?