Can speakers be too good?

Now that I have over-improved my house, I am on to my stereo. I have what is, for me, probably my final 2 channel front end: Sony SCD555ES CD/SACD, Musical Fidelity A3.2 Integrated, Music Hall MMF7 table, Kimber Kable interconnects, Monster Cable power center. My thinking was to get the best quality electronics for the money, which I think I came pretty close to doing, and then concentrate on the speakers. I currently have PSB Image 7PT. I listen to mostly singer/songwriter, jazz, blues, alt country, roots rock. Mostly stuff that is not demanding in a dynamic or low frequency sense, but places importance on spaciousness, imaging, naturalness in the mid-range, etc. Also, my room is fairly small – 11 x 18 x 8.

My question for the forum: Is it possible to spend too much for a speaker to finish the system? (Within reason – I am not looking at anything in five figures.) I am a musician with a fairly well developed ear, but I am definitely not into chasing the last 0.5% of resolution at any cost. I have always been able to hear more of a difference between speakers than between electronics, although I can hear the difference between, for instance, my generic Sony DVD player, previous Cambridge CD player and Sony SCD555ES. I am thinking of a very high quality monitor in the $3 - $5 k range (basically equal to the entire rest of the system). Candidates would include Dynaudio Special 25, JM Lab Mini Utopia (used), Spendor 1/2e, B&W N805 Signature, Tyler Linbrook Signature, Totem Mani2. (Have heard some, but not all. Just giving possible examples in the price range.)

Does this seem like the right allocation of funds? Will I be able to get the most out of these speakers with my existing front end? (FYI - I am not likely to change the guts of this system anytime soon, although I would be open to tweaks/adds such as cable upgrade, power conditioning, outboard DAC, phono stage, etc.) All thoughts are welcome.