When looking from a birds eye/macro/overall perspective, sure this is true of course, that the winners will more likely come from a retailer that does higher volumes of sales. However, from a micro/case-by-case perspective, this in no way increases your chances of actually winning past the statistical odds, when we are talking about buying 1,10, or even say half the tickets in circulation. It is exactly the same whether you buy all your tickets at Publix vs Bobs Bumpkins store. I know most here know this is of course the case, but it's good to reiterate I think, as some get caught up in these sorts of ideas (e.g., buy at a place that has higher volumes of sales - you're chances are higher! Not in any way accurate; complete and utter bubkus). Of course that's not to say that there are not plenty of ways to slightly improve your chances of winning big, detailed in both the FL scratch and other of the scratch threads here, such as targeting print ranges based on previous top prizes, etc. There are plenty of ways to play smarter, but where you buy (all other factors being equal; and also setting aside any perceived advantages of say geographical targeting etc and definitely setting aside any range targeting, or that factor being equal ), e.g., high volume seller vs low volume seller as the only disparate factor, has exactly zero statistical deviation as to your chances of winning between each store.
think of it this way. You buy an assortment of 500k tickets from each of say 500 stores across the state. Yes, more of your winning tickets are likely to come from the higher volume selling stores, say Publix or Winn Dixie but that's because 300 out of the 500 stores you bought from were Publixes or Winn Dixies, and not because any one Publix had any inherent statistical advantage over Bobs Bumpkins store.