Improving on the performance of a Vinyl LP Source does require the consideration that a considerable outlay may be needed to acquire equipment that will noticeably surpass a already existing equipment.
The performance that is achieved as a result of the restructure of the system will hopefully be quite impressive and wanted to be maintained as a keeper.
In the field of Digital there are opportunities to produce a Digital Source that can compare to a Parity or Surpass a Vinyl presentation for the impression being made on the quality of the presentation.
With Digital it is quite possible to achieve this with an outlay that is less than the cost attached to a MC Cart' from certain Brands Middle to Upper Middle Models in the Cart' Range.
With a budget of 4K and your reports that the in use Digital Source is capable of showing itself as a Betterment over the Vinyl LP Source, a small proportion of the 4K Budget allocated to the furthering of the performance of the Digital Source, might just provide a Digital Source that any selected Vinyl LP Source might fall short of in making an impression that is Parity during a comparison.