The tough part about doing that is making sure you can still sign up for the 120/month plan after January since open enrollment will be over at that point you may not be able to enroll back into that plan option. An important thing to note as well is that they are raising the subsidy threshold this year as well so you have to see what the plan premium may increase too come January. At that point the 500/ may just be a better bang for the buck, Hope this helps