When they bought the new, three-story rowhouse in June 2014 for $344,000, Silver knew the value of the land was $7,500. He had done his homework. So he freaked out when his 2017 bill valued the land at $100,890 - a 1,245 percent increase. That means he owes $1,412 this year - a 14-fold increase over the $101 he paid last year.