That is how I transitioned it as well. Once I was spending a regular large amount with XYZ over a period of years, I was able to use that to get a budget for remote render towers and more equipment and we moved it in house.
Now that I’m back on the consulting side full time I know my engagements take 3 shapes 1) building up design enough for a company to in house it 2) extending an in house team’s resources or 3) my favorite, tacking an difficult advance project an in house team doesn’t have time for… a rendering house operates in kind of the same way.