Chony..and this is what makes Yamaha smile...

Respectfully....make a list of the "improvements" from one Tyros to the other...and divide it into the figures you used for your personal example...Basically a $1,200 loss..for a few more SA sounds and some corrections that should have been fixed via soft updates..(but not possible, in Yamaha's plan)..
Hey I am all for having a new keyboard, buy an automatic purchase because they released a new model with very small positive changes...nope ..not for me..

If you (meaning anyone) were happy with a Tyros..why the need to sell it off for the hope the newer model will make you happy...this tells me most folks are not happy with their keyboards..


The other side of the equation..guys like Diki..remain content with their keyboard choice (after comparing other boards)...and remain content for 9-10 years..this also tells me about different product lines too..

A $1,200 loss on a keyboard would be something I would expect after using it for 10 years...not a single year...
BYW" even after selling off my 10 year old G1000...my depreciated loss was only $600.. ....and that loss was made up on my purchase price of the G70...

The Tyros price , nearly 3 times the price of the PSR 910..also proclaimed to be as good or better for their needs ..by..Yamaha owners...so how can that bee justified ..to purchase a new Tyros every 2-3 years...the middle model can do the same job...some say better...
Personally I would always take the top model over the mid line model...

Chony you are correct ...buying right makes a difference..I sold my Tyros 3 after 2-3 days...for $2,700...and still made a profit..