Ok, that's a good price if those are the kit components you want to use. The problem is, they don't tell us much about the controller other than it's rated 30 Amps max. Experienced builders these days are tailoring their controllers to their build, whether it's an Infineon that can be paired with a Cycle Analyst or one of the new Sine Wave controllers, that w/ their display, offer a ton of info and flexiblity. So even if you are ok w/ a genaric controller, there still is the battery to consider. I don't think many experienced builders here would get their battery off Aliexpress. So if a guy is going to order a battery from somewhere else, that is a another freight cost that has to be added into the total build cost.
Now back to your original question; BPM vs Mac?
It is generaly thought that the Mac is better quality, more refined.. In terms of power handling, a BPM is good for system that can have the cruise speed into the high 20's MPH, while the Mac, with enough battery and controller behind it, can get into the low 30's mph range.
So maybe a better comparision would be this kit vs a custom selected Mac kit from a prefered vendor like EM3ev, whose owner Paul, is a member here. Now, to select a kit from him, one needs to add options, which adds to the cost, which I'm not going to do a side by side comparision here. But for the added cost, one can get exactly what he wants, with real dealer support. And while not cheap, EM3ev's batteries are considered some of the best available.
So can this kit be a good deal? I would say; "it depends".