For low-wage, unskilled jobs, yes, it does have a lot to do with it. Americans have proven unwilling to pick fruit in horrible conditions for little to no money and have also proven unwilling to pay higher prices for fruit that we'd see if wages were increased. It's the Wal-Mart paradox, except instead of Chinese workers in China it's Mexican workers in the southern US.
This still does not change or have anything to do with the fact that employers have legal routes to obtain legal workers. Because they can raise the wages high enough to entice Americans to work for them or they can petition for migrant workers.
Besides that the cost of labor has little impact on prices. So this Tomatoes will cost 5 dollars a pound if they have to hire legal workers is nothing more than fear mongering by pro-illegal scum.
Local News | Low-paid illegal work force has little impact on prices | Seattle Times Newspaper
More than 7 million illegal immigrants work in the United States. They build houses, pick crops, slaughter cattle, stitch clothes, mow lawns, clean hotel rooms, cook restaurant meals and wash the dishes that come back.
You might assume that the plentiful supply of low-wage illegal workers would translate into significantly lower prices for the goods and services they produce. In fact, their impact on consumer prices — call it the "illegal-worker discount" — is surprisingly small.
The bag of Washington state apples you bought last weekend? Probably a few cents cheaper than it otherwise would have been, economists estimate. That steak dinner at a downtown restaurant? Maybe a buck off. Your new house in Subdivision Estates? Hard to say, but perhaps a few thousand dollars less expensive.
The underlying reason, economists say, is that for most goods the labor — whether legal or illegal, native- or foreign-born — represents only a sliver of the retail price.
Consider those apples — Washington's signature contribution to the American food basket.
At a local QFC, Red Delicious apples go for about 99 cents a pound. Of that, only about 7 cents represents the cost of labor, said Tom Schotzko, a recently retired extension economist at Washington State University. The rest represents the grower's other expenses, warehousing and shipping fees, and the retailer's markup.