If I had $100,000 handy, I would bid for the Sea Shadow, the stealth ship that DARPA built for the US Navy in 1983. It's now for sale at GSA Auctions. The original price tag: the US Government paid $195 million to Lockheed Martin to build it. And you get a HMB-1 Mining Barge too in the package too.
THE EX-SEA SHADOW (IX-529)
YEAR BUILT: 1983
BUILDER: LOCKHEED MARTIN
OVERALL LENGTH: 164 FEET
WATERLINE LENGTH: 118 FEET
EXTREME BEAM 68 FEET
WATERLINE BEAM: 58 FEET
MAXIMUM NAVIGATIONAL DRAFT: 15 FEET
DRAFT LIMIT: 15 FEET
LIGHT DISPLACEMENT: 499 TONS
HULL MATERIAL: STEEL HULL AND SUPERSTRUCTURE
DIESEL ELECTRIC PROPULSION SYSTEM
NUMBER OF PROPELLERS: TWO
Needless to say, this ship would be perfect is you want to be a superhero or a supervillain.
The price will keep going up, for sure. It started at $50,000. But it will not get anywhere its original price tag. The reason: the US Government doesn't want you to keep it in its original form. If you want to buy it, you will have to destroy it! It has to be converted into scrap:
THE EX-SEA SHADOW SHALL BE DISPOSED OF BY COMPLETELY DISMANTLING AND SCRAPPING WITHIN THE U.S.A. DISMANTILING IS DEFINED AS REDUCING THE PROPERTY SUCH AS IT HAS NO VALUE EXCEPT FOR ITS BASIC MATERIAL CONTENT.