Is zakat obligatory on goods sold at a profit, knowing that the seller is not a merchant and that this is a rare occurrence? If so, what is the amount of this zakat and when is it to be paid?

The zakat on the aforementioned money must be paid once a full year has passed since its principal was acquired, because the devices were purchased with the intention of trading. Zakat is obligatory on the principal amount and whatever has been added to it from profit, other money, or trade goods. The amount of zakat is one-quarter of one-tenth (2.5%), and accordingly, the zakat on all the money mentioned in the question is 1782.5. Zakat must be paid immediately once a full year has passed on the principal amount, and postponement is not permissible.