Likely to be the difference in insurance costs!
Probably. However, I would consider it normal if a less-than-100-hour pilot would join, that he/she would pay the premium excess (if any) him/herself.
So I would not rule out low-time pilots on those grounds per se.
Obviously if it's a rather complex type you're going to want a little more experience (in general and on type) than for your average spamcan.