Depends if your dojo is in Hollywood…then private lessons are the rule, dojo's are the exception (just kidding)
You will learn the basics (up to shodan) way faster with one-on-one tutelage than you would in a group setting. Maybe like 4 times faster or more. Don't forget all of the old guys learned that way -- Ueshiba himself. That's why paying guys like Takeda was so expensive, because they didn't usually have a group to spread the cost across (plus there was always the aspect of "secrecy" in those days, where they wanted to be the only one to get the secret techniques).
The reason we train in groups is two-fold:
One, teachers have to maximize their time. They only have so many hours to teach, and many people that want to learn so…
Two, it spreads out the cost making it affordable. Just imagine if you had to pay the full fee for Mr.Seagal yourself instead of spreading that cost across all the participants of a seminar? Few people (except for Hollyweird actors/actresses) have that kind of disposable income.
So if you can do it -- do it! You will not regret it. You can always get exposure to different body types, etc. by visiting some dojos as well. Ideally private training mixed with group training would rock.