You've got a nice system and you'll hear the benefits of an upgraded turntable/analog chain. However, the Scout is a high value product ( I had one for several years) and it sits in a sweet spot on the price/performance curve. IMO, going up the performance ladder from where you are now is going to be a case of the proverbial diminishing returns for exponentially greater dollars spent. That said, it's more complex than "how much do I need to spend." More than any other aspect of audio, analog done well is a synergistic amalgam of components that takes some experimentation and guidance to get right.
As to specific advice, I know people have a natural tendency to self-validate and recommend what they own and I'm going to guardedly do the the same. I was able to purchase a used German Acoustic Signature table for a very decent price, far lower than the price of new ones. There have been a number of Acoustic Signatures for sale on this site over the last year going for around 50% of new cost. There have been some reports of A.S. having quality control issues with their electronic motor control units in the past, not sure if this is a widespread problem or not. Mine has been rock solid reliable FWIW. VPI is a better known brand and service is more readily available and that plays into the brands better value retention I imagine. So, how much do you have to spend to improve over where you are now. Depends. Are you join to buy used or new? Buy a well known brand like VPI or a lesser known brand? There's not a simple answer.
As to specific advice, I know people have a natural tendency to self-validate and recommend what they own and I'm going to guardedly do the the same. I was able to purchase a used German Acoustic Signature table for a very decent price, far lower than the price of new ones. There have been a number of Acoustic Signatures for sale on this site over the last year going for around 50% of new cost. There have been some reports of A.S. having quality control issues with their electronic motor control units in the past, not sure if this is a widespread problem or not. Mine has been rock solid reliable FWIW. VPI is a better known brand and service is more readily available and that plays into the brands better value retention I imagine. So, how much do you have to spend to improve over where you are now. Depends. Are you join to buy used or new? Buy a well known brand like VPI or a lesser known brand? There's not a simple answer.