You'll come out about 2k ahead vs selling/trading as is. Plus you'll get to run it awhile....(a couple years?) if you choose.
There are 3 ways to "rebuild". On a fairly low hours motor you can simply repair the damaged cylinder, inspect everything else closely and re-use what you can after determining what caused the failure and rectifying THAT.
OR you can have all 6 cylinders freshened up (bored or honed) and all new pistons, seals, Reed valves, plus rectifying the original cause of failure.
OR you can go full-out top to bottom remanufacturing, replacing everything on the entire engine that can wear or degrade, regardless (except the crankshaft of course). Fresh paint, ect. But you only wanna go that route if you plan to keep it and pass it down to your kids because it is going to cost about 1/2 of what a new motor would cost.