Our PTA has done Market Day sales for years. For the last 5 years or so, our sales have been basically flat, earning us about $350 per month, or around $3200 per year (sometimes we have 9 sales, sometimes 10 depending on the calendar). Not bad money.
It is a labor-intensive fundraiser, takes us about 60-90 minutes to unload and sort orders, then a 90-minute pickup time after school. But we have found it useful for recruiting new volunteers. We get those new Kindergarten and first grade moms with younger kids, since they can bring their little ones along. (Our school still has a fair amount of stay-at-home parents.) And we've had good Market Day reps over the years.