buynumber.io is four cents a number, which makes me suspicious

Four cents. Four! Everywhere else is ten to twenty for the same target.

Bought thirty to see what would happen and about twenty landed a code. Is that normal at this price or did I get a good night?

Two in three is normal down there, and it's still cheaper per delivered code than the ten cent ones. That's the number to track, not the sticker price.

What you don't get is support. Automated end to end — fine while it works, nothing to appeal to when a batch dies.

You bought thirty lottery tickets and won twenty. Yes. That is what four cents buys.

Actually is the same for me, maybe 60 percent. For LATAM numbers is worse, maybe 40. Depend very much the country, nobody say this.