What we run
Division climbs on whichever of your ranks you want moved. Competitive wins on your own account. The ten placement games that decide where a season starts, and the fifty Quick Play wins that unlock the mode in the first place. Golden weapons, which cannot be bought with money. Battle pass tiers before the season takes them away. And an hour with a Grandmaster if you would rather learn it.
Priced per division, because every division is the same size
Nine tiers, five divisions each, and since Season 9 the same amount of progress in every one of them. That makes a division the honest unit to charge by, and it is why there is no per-tier price list here: a tier is just five divisions and pricing it as one lump hides which five you are buying.
You have three ranks, maybe four
Role Queue gives you a separate rank for Tank, Damage and Support, and Open Queue gives you a fourth on top. They move independently. Every order here asks which one it is for, because buying the wrong one is the single most common mistake in Overwatch boosting and it is not a cheap one.