And if you want to dig deeper, the actual VFX budget was probably around 4-5M:
All 610 of the film's visual effect shots were handled by a crew of 35 artists at Shirogumi's Chōfu studio,[28][74] under the supervision of Yamazaki and direction of Kiyoko Shibuya.[23][24] According to the Los Angeles Times, between a quarter and a third of the film's budget was spent on visual effects.
Generally speaking yes, Japans labour laws can be critized heavily for creating poor working conditions for VFX artists, but if you want to believe the director and the crew of Minus One, this doesnt apply here:
Yamazaki remarked that Japanese studios are either dubbed "white" or "black", with a "white" studio being one that "doesn’t exploit its employees" while a "black" studio "makes you work overnight at all hours and really doesn’t pay you well". Shirogumi, the studio responsible for the film's visual effects, is literally named "white team" in Japanese, which Yamazaki suggested means that "we want to believe we are setting up standards and an environment that is very workable for all the artists and everyone who is with us here today". Moreover, he emphasized that the visual effects team had not been mistreated and the team avoided working long hours (mentioning that it is a "very welcoming environment" anyway even if they work overtime) and cited how they assembled a kitchen in the studio to make it "more comfortable and cozy". Yamazaki also spoke of his hopes their visual effect budgets would increase in the future and that this could drive further improvements