Yes, to run Mac software, you need a Mac.
Similarly, to run Windows software, you need a PC.
Macs can be had (new) from about £650, PC's can be had for a bit cheaper (new), or you can go secondhand of course. The prices can go up a lot depending on the machine specs you want.
Either way, these days you get a lot of power for not a huge amount of money, you don't need spend two grand or more to get in at the ground level, regardless of the platform you choose.
And you're right, some people cannot afford to buy any computer at all, so a DAW probably isn't for *everybody* if we're going to be literal about it.