As someone who employs developers on a regular basis:
Full stack developer, long term projects 160 hours / month : R180 - 230 / hour. If a developer hits their hours, they get 230, if not, 180.
Short term projects up to 20 hours: R300 / hour. Generally this will be to lay down a foundation that my regular developers will work on.
R700 - R2000, large corporates will definitely pay these prices, but not a long term solution for small to medium sized businesses.
At present, for blockchain related work, the top guys in the US charge $300 / hour.
At the end of the day it boils down to what someone is willing to pay and not what a developer thinks they are worth.