quick ?

Would having to replace something concerning the ABS, like one of the sensors, be expensive?

what do you consider expensive? $100? $200? $50?

I would consider 300-400 bucks expensive. I hopefully it can be delt with for a cheaper price.

Call up a dealership and find out. An ABS sensor isn't likely to be too expensive (less than $100, i'd guess), but they'll charge you up the wazoo for labor. Call around because it varies by shop.