According to Ukrainian media, the Marichka is a self-developed system made by volunteer engineers (so called AMMO UKRAINE) with donations. The media platforms claim that the estimated cost of the UUV is about UAH 16 million, which is equivalent to $433,000.
More details on this UUV (unmanned underwater vehicle)
https://www.navalnews.com/naval-news/2023/08/ukraines-new-underwater-drone-marichka-breaks-cover/