Tom-
Cabela's is a reputable source for fine used firearms, visit the 'gun library' on their website
There's a Cabela's in Hamburg, PA which features an on-site fine gun room.
16bX16bX8x57r Greifelt, $4000 At the same store there's a "three barrel gun company" drilling with a 32-40 rifle barrel - likely a 12bX12b, also $4000
Also, in Wheeling, WV
German Boxlock Drilling 16ga x 16ga x 9,3x72R, $3199 If you find any gun in the main Cabela's
Gun Library , you can have it shipped to a gun library near you for your inspection.
I found twelve different drilling configuration hunting guns in the
Miscellaneous category right away.
Many of which are below the $5000 number you were discussing above.
I strongly suggest you look into your local hunting regulations, and the regulations of the areas outside your local area that you would consider hunting with a Drilling, Combination Gun, or Cape Gun. Make sure that it's going to be legal for you to hunt your hunts with such a firearm (cross species hunts -- consider seasons and restrictions!), also consider the array of action systems and safety systems on the guns and evaluate where your level of comfort is around 'Safeties' and/or 'Safe Carry'
Consider the game you'd want to hunt with such a system, and from there you might want to look into the ballistics of the array of cartridges that you see in the aforementioned twelve-gun battery (and that's just Cabela's stock).
That will give you a good start -- a peek into what you'll find these guns chambered in, then narrow your search to focus on getting a gun that'd actually work out for the kind of hunting you want to do.
For instance, if you were thinking a 20b gun would be great because it's light -- and you'd 'make up for the small gauge with magnum loads' think again!
You're not likely to find a drilling in your price range chambered or proofed to handle the heavy-hot-high pressure 20b magnum loads...
Or (again for light weight's sake) find something very light but the rifle is chambered for 32-20 (or even 25-20) will that be adequate, or even legal in your hunting grounds?
Can you see well enough iron sights to hunt with a rifle?
If not you're going to be shopping for a drilling that's at least set up with a scope mounting system -- and if it doesn't have the scope, consider the price (high!) of having a scope and special rings fitted to the mount system -- this ain't no weaver mount on a Rem700, no way!
Then, once you have the rules/regs/ballistics/price range end of your search sorted it's time to go handle everything you can find in as many action types and configurations you can find.
Drilling configuration guns are great -- and many of the ones you will find in your price range that fit the list of requirements are going to be nicely hand made guns -- hand made for someone else! Make sure you'll be getting into something that'll carry, shoulder, and point well for you or you'll then also be looking at having stock work done to get it to fit you too!
Don't let this cold pail of quench kill your interest.
Consider this the very short course on the drilling, from a guy who's in NO WAY WHATSOEVER an expert on the subject. I do however know enough to have pointed these things out to you this far.
Good success to you in your search.
Let us know what you come up with.
--Tinker