If your screens use the rubber bead to hold in the screen, replace them yourself - it is cheap and easy. Just get yourself the specially made inexpensive tool with a wheel that allows you to push the bead in.

Remove old screen and bead.
Get screen and cut to a little bigger than the window.
Secure in place with the bead, pressed in with the tool.
Trim the excess off with a sharp cutting tool or razor.

Don't put the screen on too tight or it will deform your screen when you push in the bead. Best to leave it a little loose so it tightens up just right.

If I had to pay for every screen needing fixing, I would be out about $500 or more by now. Kids, dogs, and cats, take their toll.

Many hardware stores repair screens/windows.

Like the previous poster said, DIY screen repair is easy if the screens have replacxeable bead---you can buy the beading tool, new bead(a good idea), and screen at home improvement/hardware stores.

A pair of scissors and a utility knife complete the tools needed.

You can also get all the stuff you need at the home store to make entire brand new screens if you can't just replace the screen material. I made several screens for my home where none existed and they were easy to make and inexpensive.

when replacing the spline (bead) bring the old spline with you to the HW store. Splines come in different thicknesses.