With any setup, you'll have to get used to it and learn how mixes made on it compare when played on car stereos, large home systems, boom boxes, cheap headphones, good headphones, home theatre systems, club PA systems, etc...
It is helpful to use the most accurate monitoring available to you, and the more accurate your monitoring is, the better chance is that subtle but important editing modifications like EQ and dynamic compression will translate correctly.
However, you will need to learn to "hear through" or "hear around" the personality quirks
of your own system regardless, in order to develop an ear for how your mix will translate elsewhere. And the only way to really do that is to make mixes that sound correct to you, then take them and play them on other systems and make note of what doesn't seem right. You'll need to do this on a number of different systems in search of whatever issues are common to all of them, or at least most of them. Otherwise you'd simply be modifying your corrections made specifically for your system for something specifically correct specifically for another, and not necessarily making it better in general. What you are searching for is whatever doesn't seem right consistently across most of the systems you listen on. When you think you've got a handle on what that is, make a new mix of the exact same material which aims to compensate for that, then check that new mix on the same systems (and others if you can) and see if that translates better. If it does, you'll begin to internalize what to listen for when making mixes using your system - that is to say, you will learn to adjust the mix not to whatever sounds absolutely best on your system, but what sounds like what you've learned will translate best to most systems. This sounds daunting, but you are likely to internalize it pretty quickly. Car checks are good. For most folks, their best sound system is the one in their car. But listen on other systems too.
Other than that, check your mix on headphones you know well. They lie too, but you can similarly develop a good sense of in what way they lie. Some editing is easier to do with phones, other editing is best with speakers. Easy enough to through on a pair to double check whatever change you are making at the time.
Using cheap systems for mastering is a bit misleading. An accurate
system in terms of a smooth frequency response is going to be easiest to work with. What can be helpful is checking on both a big system and a small one (but not an otherwise horribly inaccurate one). Small systems are incapable of reproducing much bass, so it's helpful to listen for what happens when the bass is not reproduced fully on the small system verses the big one where it is. Small systems also usually reach their dynamics limits before larger systems, so extreme dynamics which work well and sound "life-like" on large systems may need to be compressed a bit more to translate well for playback with smaller systems.