Jobwork valuation: excise duty payable based on transaction value from the principal's sale location under Rule 10A, not cost-based charges. When goods manufactured by a job-worker for a principal are transferred to a depot, sales office or distributor and later sold by the principal, the assessable value for excise duty is the transaction value at which the principal sells those goods from that place, subject to the rule's conditions; discharging duty on a cost-construction basis by the job-worker is not correct.