Being that I live in Whitby, this was a revelation. Thank you, a million times over. (Compared to what I also found at Pusateris) - McMillan's has the better deal, and their onions were also of better quality (sweeter, bigger, each and every one a perfect specimen)
For those who have suggested MacMillan's is in Whitby, and have spelled it in the Irish way, the outlet is in Ajax. This appears to be the only source, if they still have last year's crop. Pearl onions can't be found at ARZ, Nasr, Highland Farms (east), P.A.T., or Soon Lee.