(FORTUNE Magazine) – Looking for a growth stock at a bargain price? Analysts say Alberto-Culver, maker of VO5 shampoo and other hair products, could add bounce to your portfolio -- if you know which shares to buy. Like many family-controlled businesses, the company has two classes of stock. Both trade actively on the New York Stock Exchange; Class B under the symbol ACV, Class A under ACVA. While Class B shares recently cost $25.25 each, Class A's cost $18.50. Therein lies a possible bargain. In the year ended last September, the Melrose Park, Illinois, company earned $35 million on $795 million in sales. Earnings and sales from continuing operations have increased at compound annual rates of 32% and 17%, respectively, over the past five years. The recession has left the shampoo and toiletries business limp; to protect its market share, Alberto-Culver recently cut prices and upped spending on ads and promotions. Analyst Charles Swanberg of Putnam, a Boston mutual fund company, expects earnings this year to slip 12% on a gain of 8% in sales; next year, he says, the company should show double-digit growth in both earnings and sales. Much of the growth will come from Sally Beauty, a chain of stores that sell supplies to barbers and beauticians. With 909 outlets in 33 states, it generated $326 million in sales and $20 million in operating profits last year, and has ample room to expand: Its largest competitor filed for Chapter 11 on December 31. Alberto-Culver also has a thriving $80-million-a-year grocery division. It produces cholesterol-free butter and a new low-sodium table salt called Papa Dash. Says Goldman Sachs analyst Jack Salzman: ''This company doesn't go head to head with big guys like Procter & Gamble. It does its homework in R&D, comes out with unique products, and is content to dominate niches.'' Chief Executive Leonard Lavin and his family own eight million shares of Class B stock (recently worth $200 million) and with other insiders control 57% of voting rights. The company issued Class A in 1986 to raise capital without undermining that control: Each share carries only one-tenth the voting power of a Class B share. To keep the market from discounting Class A because of its reduced voting rights, Alberto-Culver set up covenants guaranteeing that in a takeover or other change in control, both classes will be rewarded equally. The strategy didn't work: A substantial price gap has always existed between the two classes. Standard & Poor's vice president Elliott Shurgin says he knows of no other company with such a large gap. He cites Brown-Forman, distiller of Jack Daniel's whiskey, which has similar provisions on its two classes of stock; for decades they have traded at near-equal prices. Analyst Swanberg thinks the discrepancy reflects the influence of index funds (see preceding item). Class B is the stock listed in the S&P 500 and the one index funds must buy; they are the largest outside investors in Class B shares. Swanberg believes that as people catch on, the anomaly in Alberto-Culver stock will someday disappear. Meanwhile, with Class A selling at 17 times estimated 1991 earnings per share, compared with 23 times for Class B, Salzman of Goldman Sachs advises investors to go for the A's. Says he: ''You're buying the same company at a much cheaper price.''