Depending on the size of the can, At $2-3 per standard unit of alcohol, would put it at like $40-60 for the equivalent whisky bottle. So, yeah it could be.
There's a bourbon called ancient age which is made by Buffalo trace. Sells for $11 a bottle here. It's not fancy, it's just a perfectly decent bourbon for a very low price.
But a bottle of whiskey and a four pack of craft beer have different amounts of alcohol, so you could end up getting a much nicer bottle of whiskey.
Liquor store chain in my area sells 30 packs of Hamm's for $13.99. 6 of those is more than a 16 gallon keg and costs ~80 bucks, cheaper than just getting a keg