If you want it to be legitimate, you have two options, cloud based Mac solutions or cross-platform development tools.
You may consider the hackintosh approach or virtual machines if you don't care about legal stuff. If you have a decent PC, running a virtual machine would be the easiest way to go. You may never know which hardware will have driver issues on a hackintosh.
I've tried all these approaches and they all have pros and cons, but for the second group, I feel kind of guilty. I develop apps to make a living and I wouldn't want to rip off someone else for it.
If you are making a small project, cloud based Macs may prove useful. Rent it for a short time, develop your project and off you go. Don't bother learning anything new.
However, if your project is getting big, cross-platform frameworks seem to be the only alternative. The critical thing is that you need to choose wisely. There are so many hybrid frameworks, but what they do can be summarized in one sentence as "diplaying web pages in an app wrapper" and developers' negative experience with hybrid frameworks also affects native frameworks.
I tried three of these (Titanium, Smartface and Xamarin) and they all claim to produce "real native output" and in my opinion their claims are correct. You need to test and see it yoursrlf, it's not easy to describe the native feeling. In a previous comment, it was indicated that it takes some effort to learn these platforms, but once you get to know them, you can develop not just iOS applications but Android applications as well, all with the common code base. And of course, they are much cheaper than a cloud Mac. Some of them are even free. You would need a Mac only for store submission.
If you know JavaScript, try Titanium and Smartface and if you know C#, try Xamarin. Just note that for the device simuator, Titanium is dependent on a Mac, but Smartface has a simulator app for Windows development and it works better than I expected. On the other hand, Xamarin requires a Mac in your network.
