Hi Montana:
Tyros2 is a 61 note keyboard arranger,
http://www.yamaha.com/yamahavgn/CDA/ContentDetail/ModelSeriesDetail/0,,CNTID%253D59012%2526CTID%253D203500,00.html
the Clavinovas are consider DIgital Pianos that have 88 weighted & graded key action , to be precise, there are 2 series, the CLP (strictly piano and related sound, NO rhythms or bell and whistles), see links:
http://www.yamaha.com/yamahavgn/CDA/ContentDetail/ModelSeriesDetail/0,,CNTID%253D59012%2526CTID%253D203500,00.html
then you have the CVP series
http://www.yamaha.com/yamahavgn/CDA/List/ModelSeriesList/0,,CTID%253D203600%2526CNTYP%253DPRODUCT,00.html
The Tyros2, PSRs and the CVP series are compatible in their styles, remember that each one has a diferent internal voice map, so, keep that in mind. They share a very similar USER interface, FRIENDLY.
And as far goes price, you must go to an autorized dealer, remember is not only the machine, make sure you will have customer support from the dealer, in other words, make sure they know their product, and you will be able to notice when they Demo the unit, if they have a hard time finding a voice or style, you are in trouble...well, that will tell you that if they are not familiar with their product, you can not expect a lot of help from them.
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mdorantes