If you are buying a route of work that is established and is worth the money it’s worth putting in the effort to make sure you get to know the customers over a few months,anyone serious would or should do this.
You’re talking about average work paying 3-6X and taking a chance,I’m not talking about I don’t fancy doing them anymore there a pain in the butt I’m talking about quality work worth decent money a ready to start earning decent money from the off.
If it took you a year only to earn back what you’d paid after that it’s a built up business earning,imo far better than canvassing average work that returns the same for cleaning 30-40 jobs a day over half a dozen.