That's not entirely accurate. I can make upwards of $25 a sale from dropshipping alone and it certainly can go higher.
$5 is the average profit if you are selling in a very crowded market.
It depends on what you're selling, where, and when.
Key thing about dropshipping: It brings in alot if you locate the niche. You got to nail down your niches, and you can do that with some good market research. Then it actually becomes easy as you sit back and watch it happen. But you still must answer every question, do your best, and put in the extra hard work.
Oh, and when you buy wholesale dropshipping its the highest profit. But you still make the most by buying in bulk, that's the real only way to go. Perhaps build up using drop-shipping, but then buy in bulk and on the side find a wide range of products to feature. Fill your store and let them all come to you.