With kids' coats running over $100 and suits in the $40s and $50s, many parents are rummaging through the discount houses, looking for bargains, particularly with back-to-school shopping heading into high gear.

One person's bargain, of course, is another's high-priced spread. The Children's Wear Market, 5556 Randolph Rd. in Rockville and Loehmann's Plaza Shopping Center on Rte. 50 in Fairfax County, has a little of both, selling "designer" kids clothes at a 20 percent discount. A plastic red raincoat goes for $5 even, but a little boy's sports jacket sells for nearly $25.

Here are some other observations on the discount scene.

Take the same $25 to Kids Wear Outlet in Fairfax City, and your son gets away with a three-piece suit. It will not be accompanied by a great deal of service, however. The cramped store has four over-used dressing rooms and salespeople more intent on ringing up prices than doling out information.

Marshall's Department Store in Alexandria also offers three-piece suits for $25 (when you can find them), as well as $10 dresses for little girls. That's $5 under the price at J.C. Penney's. Marshall's salespeople answer questions, and their prices run about a third under the usual retail shocker.

Saks fifth Avenue cuts prices by a third during seasonal sales. One mother who watches the papers for such sales says, "It makes better sense to buy good quality at reduced prices than poor quality at standard prices."

Her favorite clothing bargains came from Just So in Foxhall Square, 3301 New Mexico Ave. NW -- their sales cut prices up to 75 percent.

Mary Murphy, children's department manager for Saks' Chevy Chase store, agrees with this approach:

"We sometimes run a sale on Fisher coats, reducing them to about $50 for the 4-6x sizes and $80 for the 7-14s. These coats are well-made; last the child for two years, and make great hand-me-downs -- you really get your money's worth."

When children are quite small and growing bigger by the minute, it makes little sense to sink money into something that may only be worn for three months. Hand-me-downs become the mainstay of most mothers, prompting one parent to ask, "Who buys this stuff in the first place?"

How do you get yourself on the hand-me-down circuit?

"Some people are afraid that they may offend you offering their old castoffs," says Barbara Nyman of Arlington, a mother of three, "so they impersonalize it by working through thrift stores. But I don't have that image -- they know they can't offend me."

Sandy Melton of Arlington, a mother of two, advises parents to "give if you want to get. Use your church contacts, your playschool, your neighborhood, and the park crowd to let parents know that you're willing to share clothing."

Annette Reed, executive director of the non-profit D.C. Council on Clothing for kids, reminds parents to be tactful when accepting these clothes. "Remember that clothing is very personal -- what is beautiful to you may look horrible to someone else. The council never refuses any donations of clothing."

Her organization has been distributing clothing to low-income families for the last seven years through their boutique at 2728 Sherman Ave. NW. Families must be referred through schools or the Department of Human Resources and must call in advance (232-0700) for an appointment.

Reed and others offer these hints for making the most of the clothing you already have:

Cut the sleeves off a dress to make it a jumper.

Add a wider belt to a slightly short dress.

Cut the buttons off a double-breasted blazer and make it single-breasted.

Lower the hems on dresses.

Cut the legs off pants and make shorts.

Use pretty patches on knees and elbows.

Remove the feet from lightweight pajamas and make summer pajamas.

"With inflation the way it is," says one mother, "You have to get devious about these things.

"So be as nice as possible to anyone with a military (Px) card, worry out loud about money in front of your inlaws and develop an intimate circle of friends whose children are the same sex as yours -- but slightly older.