@hysteve , getting a system (room included) to image correctly is very difficult given the equipment most people have. Most of the electronics, cartridges and even speakers are capable of doing this at a reasonable even surprising level but the system needs to be calibrated to the room it is in and any other errors corrected.
For a proper stereo image symmetry is the most important factor. The performance of both channels (room included) needs to be identical in phase and frequency response. Early reflections have to be absorbed or speakers need to be directional to prevent them entirely. It is not important that the frequency response overall be flat but if the treble is up 3 dB in one speaker it has to be 3 dB up in he other. The channels need to be matched as closely as possible to prevent smearing the image to one side or the other certainly within 1 dB 100Hz to 12 kHz. Digital signal processing is the only way to achieve this. You can get within 5 dB with room treatment if you know what you are doing. To know what you are doing you need a measurement microphone. Digital room correction preamplifiers will do it for you. The Anthem STR is in your price range. DEQX is releasing new units in about three months. They look great but the prices are not yet available. Trinnov currently makes the best unit but it is $11,000.
Some people will never experience a system with SOTA imaging because they are digital phobic. But, you seem to be fine with it. The only thing I would change in your system other than getting a Digital Room Control preamp is, get rid of the unipivot tonearm on the VPI. It is a terrible arm. Get an arm with proper bearings. VPI makes one now that is an easy exchange.