What Sonically is the Difference between a $1,500 CD Player and a $10K-$25K One?

Kind of like the "Emperors New Cloths".  If you spend $10,000 you will talk yourself into hearing the difference.  Buy a new car or pay down your mortgage instead.  It is like anything else with audio.  It minimal returns for money spent in my opinion.  However, the wealthy folks in the group don't have to be practical.  I think it is being able to invite your friends over to tell them now look what I have.  Kind of like $9,000 speaker wire.  Wonder if you priced Nordost at $240 and Tara Labs Appolo speaker wire at $9,000 if people would convince themselves the Tara Labs to be superior.

I have an OPPO player and wonder if there is anything I could do inexpensively to reduce vibration.  Seems like reducing vibration on both CD players, pre-amps and amps make a difference.

I currently have Paradigm Prestige 85F towers.  They came with metal jumper plates.  Will I hear a significant difference if I replace them with speaker links?  I have Tara Labs Apollo speaker wire and wonder how important it would be to spend $265 for the Apollo speaker links as compared to the $125 Equinox speaker links?

Night and day difference in sound quality , if you buy from companies that have established and  doing digital for a while 
it is like the difference of a $1k turntable cartridge,and a $5k  cartridge, realism on a much higher level. That being said as digital 
technologies keep getting better the price of sound quality has 
dramatically come down ,and there are some very good dacs out there $3k or under.

There is not.  300 bucks is tops and you will get fantastic sound.  The only important things on a CD player are:

1) speed stability (the motor), very easy to achieve with todays electronics.
2) If u are using analog outputs, the DtoA converters (may be a bit expensive for top of the line Wolfsons)
3) Quality of jitter circuits.

These are all achievable in a FANTASTIC way for under $300.

The way they sound. One of the things to consider is the system and the room. It is likely that a person owning a $1500 item may not have the rest of the pieces and a room that will let the differences be heard. Now go the other way. A person who has a setup that includes a 10k-25k player would likely hear the difference if a swap out to the lower cost one was made.