I have to say that instead of investing your money in acquiring a local mac (very costly) you should consider following the hosted builder way which is a fair price to pay. If you calculate the price that you will pay for a used fair mac system it will take around 35 years of hosted builder to reach the same price. A mac will not last more than 7-8 years.
Yes, that's a cheaper option. Anyone looking for a cost-effective, simple build system should surely go for it. Though it has some limitations.
Like I don't think it has all the libraries available in this forum.
Also, you cannot download and include any additional third-party library/framework and use it via ObjC code.
You cannot use Firebase Crashlytics because it requires some manual user interaction for uploading the generated dSYM file to the google server.
Though these above points are useless if someone doesn't want to use any third-party library directly or create their own wrapper.