Probably not but it depends what you mean by "interview" and "richer data" and the diversity of your participants (and your sampling methodology).

There is a large literature on using interviews to select workers and that literature suggests that there is wide variation in the content of the interviews. The most predictive interviews are called "structured interviews" (I'll define that term below) that are designed (a priori) to measure the requirements of the job.  I don't recall the role of interviewer experience, I'm sure experienced interviewers are slightly better than novices, but the effect is relatively slight.There are very experienced recruiters and hiring managers who use crappy interviews ("What color would you be if you were a color?") and are highly overconfident regarding their ability to discern the best candidates but whose predictions are very close to chance levels. In summary: in hiring workers, research indicates that experience has a very, very slight effect.

The term "structured interview" in this literature means that all candidates are asked the same questions, often the interviewer is provided with follow-up prompts that they can choose to use or not depending on the adequacy of the candidate's answer, perhaps that the interviewer is given a "scoring rubric," each question is focused on on topic (e.g., multi-tasking) and the interviewer is instructed to make a Likert-like rating of the candidate's strength on that topic.  In summary: Structure is the main determinant of the predictive validity of an employment interview.  Another thing that helps is having more than a single interviewer (i.e., panel interviews).

However, to consider the opposing view, we also know that the single best predictor of performance (across all jobs) is job knowledge, and this finding would suggest that experienced interviewers would perform better. (We cannot say how much better without studying the job. Some jobs, like computer programmer, the best performers are dramatically better, while for other jobs the productivity of the best and worse employees isn't dramatically different.) I would predict that interviewer experience matter more for difficult/complex tasks. For example, if the average person placed in the role of interviewer fails, then experienced interviewers may be far better than novices. This might be the case if the interviewer has to seek out the interviewee, or decide which interviewee to include, or devise tactics to allow the interviewee to "open up," etc.

Even so, I have a hard time thinking that you would get richer data from 10 people than 50. It would require assuming that the data that you get from any interviewee is about the same or that the difference in performance between experienced and novice interviewers are dramatic. For example, when cognitive psychologists measure the number of items you can hold in short term memory, there aren't big differences among most people. But people's experiences, temperment, abilities, attitudes, etc. tend to differ quite a bit.

Finally, an anecdote: I don't know how you define "experienced" but a student and I collected stories about making ethical decisions as one step in a scale-building project. Our methodology was to spend about 30 minutes training undergraduates who went out and found employed people (maybe their parents or roommates) and conducted a structured interview designed to elicit situations where they had to make decisions using ethical principles.  I imagine you would consider these interviewers as novices.  We found that only about one third of the answers worked for our project. The others simply did not lend themselves to becoming an "ethics scenario" on a survey. It's possible that having more experienced interviewers might have helped, although I don't think we knew enough to give them the guidance that they would have needed to apply their experience. (And if we had better guidelines, we could have refined the training and interview guide given to the students). I think it definitely benefited us greatly to have a greater quantity of interviews.