'tis mine
yes, twice actually
All depends on where and when you find it
Secondary is generally $11-1400+ for a bottle depending on how old (the pre BT ones are double or more that). But retail isn't that bad. If you have the time and coin buy the whole BT antique collection and then part the others out and you'll do better but still pricey.
Pappy 23 is 16-2300+ on secondary
Birthday bourbon is 850-1600 depending on year.
The difference is the taste of each of those. WLW is intense vanilla, brown sugar, caramel, etc similar to Eagle Rare but deeper and more complex.
Pappy 23 is too oaky and I've never had it but the people who have who's palate i trust all say it's over priced in secondary and no where near it except for the mystique.
OFBB varies from year to year and from great to damn good. Lots of candy flavors, very sweet, but a completely different flavors than the others. I've had pours of a few of them.