On Feb. 18, Miami-Dade County County Commissioners will discuss whether to begin negotiations with a private consortium for a new $2.3 billion trash incinerator. That’s billion, with a “B.” And if history tells us anything, it’s that the final number rarely goes down.

More than 340,000 households currently pay about $700 a year for county trash service. Financing $2.3 billion over 30 years — before you layer on operating costs, maintenance, insurance, legal fees, consultants, and the always-convenient “unexpected conditions” — could easily push annual system expenses into the hundreds of millions.