For me and my experience I bought and sold a lot of ukes in my first year of playing. I never could afford to spend more than $500 on a uke and I ended up selling a lot of nice $500 range ukes and keeping my Mainlands. Why? There just wasn't enough of a noticeable difference and I felt more comfortable and was happier playing my Mainlands that all cost under $200. I have a Kamaka that really is my best uke but new it cost at least three times more than a Mainland. I can't say that it is three times better. I can't comment on the higher end ukes. I would imagine they play smoother and do sound nicer but I personally can't afford them and like having several $200 ukes rather than one $1,000 uke.
"Music self-played is happiness self-made"
Sopranos: Donaldson (Myrtle), Kamaka (Koa), 2 Mainland's (Cedar/Rosewood & Mahogany),
Nahenahe (Mahogany) (Thank you Stan)
Concert: Mainland Classic Mahogany (low G)
and one flashy white and gold Titano accordion