Should I try to improve speakers at $2000.00 range

Disagree with Doug.
Most speakers made today cost twice as much as 10...20 years ago so @2k doesn't seem to be argumentative enough to replace current speakers at all.
It's only $3400 after Celestion speakers are sold so the question still remains weather it's possible to find an upgrade(used might make much more sense) spending $3400 to the current Celestion?

...Had been long time in desire to listen to Nola Contender with powerful tube amp such as QuickSilver M90.
The new price is exactly $3400 I've mentioned in the previous post.
Another way is to wait to double your upgrade budget and shoot for Nola Viper II.