What kind of cheap mac mini can I take to build an iOS project?

Question

iOS

I am working on ionic projects for mobile platforms. For android I collect under Windows. But with iOS plug. I want to take a cheap and / or used macmini for assembly for iPhones and iPads, but for a long time I have not been in the topic of apple products. The option to rent remotely is already there and I don’t like it. In general, you need a piece of iron to pull the assembly and so that there are no problems with it. And, yes, I would also like to have the opportunity to tinker with it in my free time in swift.