Those are the best options but, IMO, I don’t think it is justified.
Today, Safari is the most problematic browser, since every other browser is based on a common engine (Webkit, Gecko/Quantum, etc.). It wouldn’t be so problematic if we could test it without owning a Mac/iPhone!
So, my suggestions (based on my experience):
I suppose you already know this, but using the responsive view on Chrome/Firefox/Opera/Edge almost always ensures that the mobile version looks exactly like it’s shown.
You should get a cheap/old iPhone model (5s or the oldest long term support). If your website looks fine, usually on Mac will too. On the other hand, if you can afford it, get a Mac (a friend, share screens, etc.) just for testing. With a Mac you could test the mobile too without a phone.
A reset CSS is a must too, since they usually remove inconsistencies among different browsers.
You can have virtual machines with the OSs you need (this is what I do). You can install Linux and Windows (you require a valid license to install it on a VM, but you can find some cheap keys) and Mac on a VM (hackintosh), though it’s illegal if the hardware is not a Mac.
We should push apple (change.org?) to provide a way to allow developers to test websites on their browsers.
I hope this helps you a little ,