SIX DECEMBERS AGO, when the consumer affairs committee of Americans for Democratic Action issued its first annual toy-price survey report, a lot local merchants didn't take it very well. Because the report showed some striking differences in toy prices at various stores - and generally higher prices in stores downtown, where shoppers are relatively poorer - those merchants with the higher prices were quick to discount the survey (if not their toys).

But this year, according to Ann Brown, who heads the committee, the most dramatic news is the turnaround in both toy pricing and the attitude of the toy outlets. "In 1977, it's a consumer's market," she reports, noting that shoppers throughout the area will find the price competition refreshingly hot. What's more, stores have become constructively conscious of the annual survey's impact. For example, Tunz-a-Fun, a discount outlet in Alexandria, specificallu requested to be included in this year's canvass.

n all, 57 different toys were surveyed in 33 stores this year. "Our aim is not to bring all stores to one low price level," says survey committee head Debbie Wager, but rather "to inform the consumer what the prices are, and where." Survey committee members hasten to add that their report is not intended as any endorsement of the particualr toys that they checked. In fact, the report ought to be read in its entirely, for it contains many helpful bits of information (single copies are available by calling 638-25-45).

Among other things, the report urges shoppers to consider "play value" - which is to say not just the potential hours of plesant play a toy may provide, but also how such play might add to a child's development. If this kind of public information about prices continues to produce livelier competition - which in turn may elicit still other helpful product information - our hunch is that neither city nor suburban shoppers are going to complain about it.