Hi Etienne,
if you want we can set up a solo trip for $100 extra (single supplement).
I will actually be leading a large group beginning of June (safari 4-7 June, 10 days Kili climb 8-17th June).
If you want, you can join that. It will save you from paying the single supplement, but as the trip is very long (and beautiful), including a night in the crater, it will be costly anyway.
So let me know what you prefer and I will set it up

Cheers,
Harry