I have a Collings guitar, which I really love. If I had the money, I would buy another.
However, for that money I would get a custom ukulele. There are at least 3 ukulele luthiers who could make something that is better.
Also, with a custom instrument you can:
1. Choose the actual pieces of wood
2. Choose the wood combinations
3. Design it yourself (if you want to)
4. Decide on the decoration and binding
5. Choose the tuners
6. etc, etc.
On the other hand, to get a custom instrument you will have to wait (several years in some cases).