It was 10 a.m. Friday morning, and I was on a mission from God.

Well, actually, I was on a mission from my editor. "Find me bargains," she said. "I need the cheapest buys, the biggest selection, and the best service around."

I knew what I had to do. I had eight hours until deadline to track down the best buys on Levis jeans, boxer shorts and Teva sandals in Harvard Square.

So I hit the street.

First stop: Serendipity on Mass Ave. Nice name and nice clothing, but no Levi's no boxers and no Tevas in sight. I exit.

Next door at J. August, my roving reporter's eye spots three styles of boxer shorts. They are cheap and not unpleasant. The best-looking pair sports a blue and green plaid design, a Harvard logo and lots of fuzzy flannel to keep you warm. The price: $16.

"It's the flannel that people want," says John C. Baestas, assistant manager. "That's one of our most popular items...usually with the young ladies. They sew up the hole and wear them as shorts."

Hoping for more than three makes of boxers, I visit Mass Army-Navy, farther down the street on Mass Ave. This place has an incomparable selection as well as good customer service. I am impressed.

The Tevas are downstairs, available in several different colors and a choice between firm and flexible soles ($45 and $55, respectively). While they sell well to summer shoppers, recent sales have been slow, says employee Jeff H. Thomas.

"During the summertime Tevas were a very hot item...People still occasionally come and ask for them," Thomas says.

Then he shows me the "Vintage Denim" or "Classic Rags"--euphemisms for second hand Levis. This "authentic recycled clothing" will set you back $17.99.

Upstairs, the selection grows even more immense. My fashion-curious eyes jump in glee around the two rooms, stuffed full with Levis upon Levis in every imaginable color, size and shape.

Classic rock accompanies my perambulation through this Levis heaven. I see upwards of 3,000 pairs in purple, red, two variations of olive green, twilight blue, hickory brown, teal, gold and the basic blues.

Jean styles include 501, 505, 512, 517, 519, 550 and Silver Tab for men; 501, 901, 512, 902 and 560 for women. Prices range from $24.99 for regular stone-washed to $40.00 for offbeat dyed colors.

"We have the largest selection and best prices," says Dave G. B., second floor supervisor of Mass Army-Navy.