I get Botox once a year.

I have a lot of muscle in my jaw, so if I don't get Botox, my jaw becomes square. I've been holding it in for a while, but I finally get it once a year. Every time I go, I wonder: the prices go up progressively, with the cheapest domestic Botox, low-resistance Botox (which is also domestic), and foreign Botox that causes no resistance, right? Will I develop resistance even if I get the cheapest jaw Botox once a year? I haven't tried foreign brands yet and usually get the mid-priced domestic low-resistance Botox. Last time, when I mentioned I was getting the cheapest one, the consultant kept recommending the mid-range one, mentioning resistance and whatnot. I am genuinely curious if this is for the clinic's profit or if they are truly worried about the customer developing resistance.