The kids want a new color, the walls have scuffs at shoulder height, and you have two free weekends on the calendar that do not match the kids' schedule. Painting one room is a job you can do yourself or hand to someone else. The useful question is not which one is cheaper in the abstract. It is which one fits the hours you actually have.
Local option: New Plan Care gives families in the St. Louis area in-home help so a parent can stay home: companionship, help with bathing and dressing, meals, and overnight care. Call (314) 405-0887.
Count the prep, not the paint
Most of the time in a repaint goes to preparation: moving furniture, covering the floor, patching holes, sanding rough spots, taping the trim, and wiping down the walls. Walk the room and list every patch and scuff. A room with many dents is a longer job than a room with clean walls, whatever the color.
Also check the ceiling. Textured or popcorn ceilings are harder to match, and paint can flake off them if the surface is disturbed. If the ceiling is not part of the plan, plan to tape it off and keep the roller away from it.
Check the room and the calendar
Ask whether the room can be empty for the whole job. Most painters and most DIY plans need the room clear for at least two days, with the door shut and the air moving. If the kids sleep in the room during the job, you will need somewhere else for them, and that place becomes part of the plan.
Look at the split week. A repaint that starts on Mom's row and runs into the kids' row means the room and the schedule both change hands in the middle. Pick a window that stays in one row from start to finish if you can.
Ask the same questions of each option
If you do it yourself, list the tools you need, the number of coats, the drying time between coats, and who will be home to watch the kids while you cut in along the edges. If you hire it out, ask for a written scope that names the prep work, the number of coats, the trim, the ceiling, the cleanup, and the paint brand or grade you will receive. Compare the two scopes line by line, not the totals alone.
Ask any painter what is excluded. Patching large holes, moving heavy furniture, and repainting closets are often extras. Ask how they protect the floor and the outlets.
Decide and write it down
Choose the option that matches your hours, the room, and the kids' calendar. Put the start date and the finish date on the shared calendar, and name the person who will check the room on the last morning. A fresh color on the wall is a good thing, and it goes better when the plan was clear before the first roller touched the wall.