excise

if i charge the rs 700 along with the material cost in the same bill then will i have to pay excise and cst on rs 700 as well

Excise valuation does not depend upon whether you raise combined bill or separate bill.

In general outward transport cost is not includibale in the value of goods. If you earn some profit in arranging outward transportation (Rs. 200 in this case) is also not includible in the value. 

if u charge rs 700 along with the same bill for material,

in that case assessable value shall be 30,700 as per excise valuation rules and deduction is available only for outward transportation cost and not for inward  and if you are not able to distinguish outward and inward charges then whole amount of transportation  charges will be included in assessable value and excise duty shall be levied.