Yamaha saxes are great instruments, but the intermediate ones are a bit over priced in the market today.
Bauhaus-Walstein are very good too as mentioned, and definately value for money.
I personally really like the Yamaha saxes. I play an old YAS62, for me it`s the perfect horn. Fantastic ergonomics, great feel, easy blowing and responds really well. - The sound, that`s down to you, but yamahas tend to give your tone a crisp bright edge. qite a pure sound.
The Bauhhaus-Walstein is more of a darker, deeper tone. A bit more complex ( I play a Walstein Tenor).
If you can stretch to 800 you can pick up a second hand 62 fairly easily and as long as it`s in good nic you should never need another alto. I doubt I will.