It's going to be expensive. Not only do you need a replacement catalytic converter, the exhaust piping will need to be replaced to fit the new converter. Call your auto insurance they may pay for it minus your deductable. A little known fact, if you own your home, your homeowners insurance could cover it, the deductible might be different though. To get your car going, a hacksaw, muffler pipe, muffler tape, hose clamps and you're in business! If its a newer car you're going to definitely get a "check engine" light.