Last week, "The shocking cost of the senior prom" revealed an average expenditure of $1,078. I wasn't the only one startled by that figure. A number of readers left some fairly pointed comments.

One parent, however, defended a $900 grad dance tab: "We feel she deserves to celebrate the end of her childhood and the beginning of the next chapter of her life."

How much to spend is a completely personal choice but not necessarily a rational one. If a school dance can cost a grand or more, how much are you prepared to throw at a wedding?

Readers and experts offered suggestions on keeping costs down. Read these tips and stay within your budget when the next grad looms.

The dress, for less
1. Go retro
. Hit the thrift store: Thanks to the "Mad Men" television show, "anything vintage is so in," says Stephanie Berenbaum, who blogs at Fabulous & Frugal.

2. A second chance. Nothing good at the thrift store? Look for a consignment shop. It's pricier, but nowhere near dress-shop pricey.

3. A long shot. My niece's classmate bought a bridesmaid's dress at a yard sale. Total cost, with tailoring and embellishment: $15.

4. Lend to a friend. Several readers say their daughters borrowed and lent formal wear.

5. Short and sweet. Floor-length gowns cost more (and are harder to dance in). Consider a shorter dress, because less can be more. Especially if you ...

6. Keep it classy. Berenbaum knows a girl whose strapless black dress stood out in a sea of teen-age bling. The sophisticated look made her the talk of the dance. Bonus: She already owned the dress.

7. Shop the clearance rack. Readers paid as little as $10.

8. Shop online. Price comparison sites such as PriceGrabber.ca can track down deals for specific styles. Shopping code sites provide deep discounts, too.

9. Craving fashion? If you must have designer wear, check out Rent frock Repeat.

More than one way to dress a guy
10. Group discounts
. Take a bunch of friends to the tux shop and ask for a price break, suggests consumer expert Andrea Woroch.

11. Use coupons. Tuxedo rental discounts are available through sites like Retail Me Not and Savings.com.

12. Buy, don't rent. Formalwear shops sell surplus suits, says reader "Dad of Eight." His son's $99 find served for three proms and three weddings, and is now being worn by a younger brother: "A classic tux never goes out of style."

13. Vintage works for men, too. Christine Martinello's son spent zero dollars on prom attire — he borrowed his father's wedding suit. The Atlanta mom called it a "retro" look but her son said the choice was purely practical: "It looks good and I don't have to waste time renting a tux."