In my experience many mid priced tuners are better than most people think. The reason is cables. In most systems I've seen, including the AudiogoN virtual listings, a lot of folks don't take FM seriously, so they don't use a high end interconnect cable, just a budget one at best; or the tuner gets the left-overs and no effort is made to find a good match.
I find cables selection with tuners just as finicky as CD players. In one system I am using a classic digital tuner that had a MSRP of $420 in 1986 dollars (I paid $35). I have tried many cables, and with the (used) Siltech ST-18G3 I am now using, it comes close to CD quality. It is a 5 gang tuner, so it also brings in the stations as well as many costing much more.
So before you dish out $1K to $2K++ for a tuner as your upgrade path, try your current one with better cables. You might be surprised.