S.B.
In MN, the court date is set when the paperwork is filed . . . not the same in TX? You also don't mention if you have legal representation or not . . . Here in MN it is just court fees if you do it yourself - about $250 plus the cost of a process server. However, if you are low income, you can file an IFP with the court and request that all fees be waived. To hire a lawyer (a good one) here for modification, there is usually a $1500 evergreen retainer - meaning that when the money is gone, you must replenish the account or your attorney will withdraw. The actual amount depends on whether the modifciation is contested, if expert witness are called and whether or not it is appealed.
Good luck!