Stas,
You want a great upgrade, from 550... to Tyros!

I'll tell you something: a lot of european and USA musics can't have a Tyros, nor a PA1X, nor a Technics KN7000. And they are music people, and they make music.

Life is long for you, because you are very young, Stas. So, go not so quickly in your desires. You may make very good music without a Tyros or similar high-end kbs. You may work and make money: then, you may buy a used but good kb, there are a lot kbs for to buy not so priced as Tyros and very good too... And little by little, you will grow in personality and music ability.

But asking for a Tyros, NOW, perhaps is not the better desire. Ask for that you may have now, not dreams. Dreams will arrive tomorrow, but now you are 15 year old...

Hope life is going to be good to you. But you must be good with life first, you know?

cheers