Here are the completed phrasal verbs using the words provided:
Students come up with an original idea.
They set up and manage a business together.
We wanted to find out about prices.
You worked together to find the best price.
We put together some sample website designs.
We didn't give up.
We looked for different design ideas online. (Note: "looked for" is another phrasal verb but "looked up" can also work in different contexts.)
We went ahead with the project. (Note: This might be an alternative if there's context for going ahead.)
Please ensure that these suggestions fit the context of the interview you are referring to!