That’s a reasonable price for getting 20Ah, but note it is not the PD version, so isn’t really a daily use type product as takes longer to recharge. So this would be good for say power outages or as a 2nd 20Ah to complement a PD version you use first and recharge more often.
Personally I’d wish Anker to stop selling this, it risks people buying it thinking it will charge, say, their iPhone as fast as possible, it won’t as will give 12W not 18W or 20W.