I'm not sure I'd like much at $20. For ~$30 you might start to get drinkable bourbon. Something like Evan Williams Single Barrel is good bang for the buck.
I've purchased W.L. Weller for as little as $12 a bottle, and it is, generally speaking, fantastic.
According to thewhiskeyjug.com, its median price is $17 for the Special Reserve.
In a marked note of irony, Pappy Van Winkle is oft-regarded as the best bourbon around, so people tend to consider "close enough to Pappy" as being a fantastic bourbon. In an interview once, Julian Van Winkle mentioned that he though W.L. Weller was "just about as good" as Pappy Van Winkle. Because Weller was, at the time, very inexpensive, and Pappy very much in the expensive category, there was a giant boom for Weller... so much so, that now some of the older bottles of Weller go for 4 figures. Hilariously, more than what it costs to buy a bottle of Pappy (though both are nearly impossible to find, and people do pay plenty for Pappy when they can find it.)
For what it's worth: what you're pitching is basically Templeton Rye (albeit for Scotch), which is also chemically "improved".