As rightly pointed out by Shri Jayaram Hiregange, there is no mention to have a single price for falling under 'Composite supply' u/s 2 (30) (whereas for falling under 'mixed supply', it is specifically mentioned that there has to be single price). But, I am not sure I followed the conclusion he sought from given legal position in the scenarios under discussion here.
Also, I respectfully differ with Shri Kasturi Sethi Ji for his views above in post at serial No. 2 read with serial No. 4.
In my view, there can also be different prices for two or more supplies involved the 'Composite Supply' where criteria is that 'a supply made by a taxable person to a recipient consisting of two or more taxable supplies of goods or services or both, or any combination thereof, which are naturally bundled and supplied in conjunction with each other in the ordinary course of business, one of which is a principal supply'.
Moreover, despite having either single price or different prices, as per Section 8 (a) of the CGST Act, the tax liability on a composite supply shall be determined in the following manner, namely:-
"a composite supply comprising two or more supplies, one of which is a principal supply, shall be treated as a supply of such principal supply"
Hence, in the subject scenario under discussion here, said supply is a Composite supply where principal supply is that of goods. And hence, secondary/incidental supply of service/transportation (despite having separate price) will be treated as 'Supply of Goods' only inviting tax-rate is those apply to the principal supply.
W.r.t. mixed supply u/s 2 (74), there has to be single price against two or more individual supplies of goods or services, or any combination thereof, made in conjunction with each other by a taxable person where such supply does not constitute a composite supply;
Illustration: A supply of a package consisting of canned foods, sweets, chocolates, cakes, dry fruits, aerated drinks and fruit juices when supplied for a single price is a mixed supply. Each of these items can be supplied separately and is not dependent on any other. It shall not be a mixed supply if these items are supplied separately.
And only because there is single price for defined mixed supply involving two or more supplies where same is not composite supply, as per Section 8 (b), the tax liability on a mixed supply shall be determined in the following manner, namely:-
"a mixed supply comprising two or more supplies shall be treated as a supply of that particular supply which attracts the highest rate of tax."
If there are different prices for different supplies involved, there cannot be a mixed supply. Furthermore, mixed supply comes into picture only if same does NOT fall under 'composite supply'.
In other words, for taxability under GST, there is no supply of service / transportation in subject situation under discussion here being same is 'composite supply' despite charging separately for the same. And entire supply is that of principal supply i.e. goods only.
These are ex facie views of mine and the same should not be construed as professional advice / suggestion.