Oh boy, here we go again.
Yes, most landlords lead their search for a PMC by focusing on cost. The assumption is that PM is PM, basically, it's the same with whichever company you hire.
I think this is basically true, with the key differences (other than arbitrary pricing differences) really being on execution. There are a few ways landlords can lose money on a rental: 1) Vacancy time. 2) Bad tenants/bad move-outs/tenants who pay late. 3) Overpriced repairs or repairs exacerbated by an incompetent PM.
Being excellent at 1-3 above doesn't cost more money for the PMC. It requires outstanding systems, process,es and company culture. Therefore, it doesn't need to cost the landlord more to hire a PMC that excels at 1-3 above. This is PM ROI in a nutshell.
It's all about ROI. Good PMs understand the necessity of speed and accuracy in PM. Prospective tenants need immediate responses, so they don't rent something else. Repairs need to be managed effectively and with systems that are foolproof. Marketing needs to be excellent. Responsiveness to clients needs to be excellent.
Company culture needs to reward integrity and competence. Hire smart people, pay them well, keep them as career professionals.
Beyond all that, you also need legal expertise. Many PMs fall short on this because it's not technically required to go out and do PM.
We could make a case for charging the most in the industry, but we turn that on its head and make the case for charging the least, while still offering the most.
At the end of the day, taking on a new door as a PM is just a guess. How much work is this property going to be? Is it going to have a lot of repairs? Is it in an area where it's easy/hard to attract qualified tenants? What's this landlord like - are they going to call me every day or week or are they going to be hands off? As a PMC, you have to evaluate the TIME suck of each door you add on, and you have to train the landlord and tenants and vendors on how to interact with your company in a way that works for everyone but remains highly efficient.