YAS-25 has a High F# key as do its successors (275; 280) whereas the 21, 23, and Vitos do not.
I have a nice YAS-25 I could be persuaded to part with (5% of sale price to forum fund).
From these student models you go into intermediate 32; 475; 480 then on to Pro 62; 82; 855; 875
For good used ones, student £400-600
Intermediate £600-1000
Pro £1000-2000
Then you have different ages and origins e.g. YAS-62 MkI, II, III; older Purple Logo (transfer on bell instead of engraving); Earlier Made in Japan; Later Made in Indonesia.
Confused?
They're all good. Some say Japan is better. Purple Logo sought after.
I've had alto, 21, 23, 25, 275, 32, 475, 62 PL & Vitos. 62 PL the best I've experienced. Vito best value IF you can find one.
As @JayeNM says, various makers made Vito (Yamaha; Jupiter; Beaugnier; Yanagisawa). Come back here if you're not sure and show us what you've found, to identify it.