This is one of the biggest motivations for going (and staying) on the Moon, Mars, and so on. Going after this object is not just an issue of money. Intercepting objects in space is
really hard. Intercepting objects that are hauling ass away and have already shown an ability to exhibit let's say 'aberrant acceleration', when we don't currently have the technology developed, let alone tested and refined, to intercept it makes the entire idea perhaps not impossible, but extremely unlikely to succeed.
By contrast when we have ships moving regularly between Earth, Mars, the Moon, and wherever else - we'll have much more infrastructure and technological development enabling us to have a much better chance of being able to rapidly react to the next 'weird thing' we see in space. And seeing how many weird things we're already starting to observe now that we've just barely begun to be able to open our eyes, I expect this is just the beginning. Consider we still lack the technology to determine whether or not there is some giant super-earth floating around in our own solar system. Sometimes in space it's much easier to see things billions of light years away than it it is to see something right next door.