Loan modifications do not cost anything if you are able to negotiate and modify the loan by yourself.  Keep in mind who the bank is representing and the modification you typically get is reducing your payment just enough to become affordable and not necessarily subjective enough to build in some extra buffer for unexpected situations (e.g. medical expenses, commission or salary reduction, etc…). 

Some other loan workouts will include an increase in payment to start repaying past due months (repayment plan) or a settling a 2nd mortgage for less than the full amount, eradicating your 2nd mortgage principal balance and then refinancing the whole loan again at a new appraised value.