How much will you spend on school supplies and clothes for your kids this year? The average American family will shell out $606.40, according to a survey by the National Retail Federation.

That is up from last year's estimate of $548.72.

The increase is because families have cut back for the last two years and need to replace the items their children have outgrown, according to the NRF.

Laura Daily and Claire Walter are partners in www.milehighonthecheap.com. They spent the last couple of weeks shopping for back-to-school bargains.

Clothing

"Thrift shops have absolutely great values. Kids grow so fast that they'll outgrow their clothing in a year," said Walter.

She found gently used children's clothing from $1.99 to $3.99 at Goodwill. She also found new Hanes briefs and panties for boys and girls from 99 cents a piece.

Walter suggest parents check out consignment shops.

The women have about a half-dozen nice ones like Childish Things in Boulder; They Just Keep Growing in Castle Rock; Mommys Merry-Go-Round in Lakewood; Kid to Kid, in Aurora; Repeats Childrens Resale in Aurora and Back On The Rack in Denver.

Huge consignment sales where moms sell to other moms are growing in popularity. The Just Between Friends group is holding two back to school sales:

Aug. 27-31 at Boulder County Fairgrounds
Sept. 3-4 Douglas County Fairgrounds

Twice a year, the Mothers of Multiples Society holds a large consignment sale. A portion of the proceeds helps the MOMS Community Outreach program which provides supplies, clothes and equipment to low-income families with multiples.

Two-hundred members fill a 29,000 square-foot space inside the the Douglas County event center with their gently used items.

The next sale is Saturday, Aug. 14 from 10:30 a.m. - 2:30 p.m. Admission is $1.

Backpacks

Walter found a new backpack at the Goodwill for $3.

"Staples office supply store will give you a credit for the full price of your backpack to use for something else in the store," said Walter.

School Supplies

Using a typical first grader's school supply list, Daily went to Walmart, Target, office supply and big warehouse stores.

"When all was said and done Walmart and Target can't be beat. It was a tie," said Daily.

The total for all the supplies was $12.50. She found notebooks for 15 cents at Walmart and a box of crayons for 25 cents at Target.

"Which everyone is closer to you is the best place really to go for school supplies," said Daily.

Immunizations

Vaccinations can also be a big back-to-school expense.

"In many cases, local health departments partner with area fire stations for Saturday clinics. Not only do the kids get their vaccinations but they can check out the cool fire engines and ambulances, play games, and go home with goodies," said Daily.

Typically immunizations are about $14 per shot, according to Daily.

She said in many cases you can pay what you can afford, because clinics generally will not turn away a child for inability to pay.

To find a low-cost clinic near you check out the Colorado Children's Immunization Coalition.

Here are few of the clinics Daily found:

Denver -- FREE immunizations 10 a.m. to 1 p.m. at Denver Fire Station #9 (4400 Brighton Blvd.) Dates: Aug. 28, Sept. 25, Oct. 23, Nov. 20, Dec. 18. Also Denver Public Health Immunization Clinic at 605 Bannock St., 1st floor. Call for prices. Open Monday to Friday 8 a.m. to 4 p.m. Walk-ins welcome. Appointments not required. 303-602-3520.
Aurora -- Clinics 2nd Saturday of every month, 10 a.m. to 1 p.m. Aurora Fire Station #2, 12600 Hoffman Blvd. $14/shot or a donation (but no child turned away). Dates: Aug. 14, Sept. 11, Oct. 9, Nov. 13, Dec. 11. 303-451-0123. Also walk-in clinics Tuesdays and Thursdays 1 p.m. to 3 p.m. 15400 East 14th Place, 1st Floor. 303-451-0123
Littleton -- 10 a.m. to 1 p.m. Douglas H. Buck Recreation Center, 2004 W. Powers Ave. (just east of downtown Old Littleton). $14/shot or a donation (no child turned away) Dates: Aug. 14, Sept. 18, Oct. 16, Nov. 20, Dec. 18. 303-451-0123.
Northglenn -- Walk-in clinics on Tuesdays, 8:30 a.m. to 10 a.m. 10190 Bannock St. 303-451-0123.
Englewood -- Walk-in clinics on Fridays, 8:30 a.m. to 9:30 a.m. 4857 S. Broadway, 303-451-0123.
Boulder -- Walk-in clinics Wednesdays 1 p.m. to 6:45 p.m. 3482 Broadway, Boulder, 303-413-7500. $14.50/shot (no child turned away).
Longmont -- Walk-in clinics Mondays 1 p.m. to 6:45 p.m. St. Vrain Complex, 529 Coffman, Ste. 200, 303-678-6166.
Castle Rock, Lone Tree and Parker -- Appointments available by calling 303-451-0123.

Daily and Walter have plenty of other saving ideas, you can check them out on www.milehighonthecheap.com