When you're cleaning up in the majors (Koepka won 4/8 from 2017-19) then your percentage is going to work out very nicely. Take 2018 for example, Koepka won both the US Open and PGA, as well as six top 10s, which brought in over $7m.
The US Open paid out $2.16m and the PGA $1.98m so, on a rough basis of 10 per cent, Elliott probably collected north of $400,000 from those two weeks alone. Then you can throw in the basic, top-10 percentages and the bonuses and the Portrush man is on a very nice gig.