Where would one go online if they wanted to buy a steam locomotive?
What kind?
Toy (32mm, 45mm, 3.5-in., 5-in.)?
Large scale “ride-on” (3.5-in., 5-in., 7.25/7.5-in., 1-ft.)?
Amusement Park sized (1-ft., 15-in., 20-in., 2-ft.).?
Narrow Gauge (2-ft., 30-in., 3-ft., meter, 42-in.)?
Standard Gauge (4’ 8.5")?
Broad Gauge (5-ft.)?
What type?
Shay, 0-4-0, 4-8-8-4, or somewhere inbetween?
What use?
Personal fun and games (ala Grizzly Flats)?
Tourist operation (ala Boone and Scenic Valley)?
Logging operation?
Commercial Freight?
Iowa Interstate RR has a couple of 2-10-2’s for sale… nice engines, standard guage, coal fired… could be a great start for a tourist operation, or some really neat animated yard ornaments!
See: http://www.youtube.com/watch?v=VKxroW2VopU
Got a place to run one? Got a place to house one? Got a good team to maintain one?
Go to “GOOGLE” and type in:
+steam +locomotive +“for sale”
YES! It IS that ‘simple’… I found SEVERAL places selling “Steam Locomotives”! 
Happy shopping!
Semper Vaporo!
Hi Semper, Thanks for all the info. It would be part historical exhibet and part playground piece. I have passed all you info along and will get back to you if we need more info. Thanks again and good luck.
There are various sources who occasionally sell, broker, and/or list steam locomotives. You might try D. F. Barnhardt, Okark Mountain Railcar, Rail Swap, Alan Keek (UK), Preston Services (UK), and Multipower International (US, but selling Chinese stuff). The Iowa Interstate locos that are for sale are Chinese 2-10-2’s, relatively recently built.
Note that anything operational is going to be well into the six figures, and seven for anything that can haul a sizeable train on a main line at reasonable speeds.
Man I had typos. It’s Ozark Mountain Railcar and Alan Keef.
If you can afford large one (standard gauge or larger) TAKE CARE OF IT!!! Few are left, and I all too often see one rusting away next to a playground or highway. It makes be sad to see things like this. If the cab will be open to the public, I say you should either take out most of the controls, leaving the basics, or put plexiglass over the control surfaces. ALSO, WATCH OUT FOR PEOPLE LOOKING FOR SCRAP. Unprotected steam locomotives are a pretty sight for people making money off of scrap.
Also, an operational steamer like the 2-10-2’s for sale would run into 6-digits, and I would not be surprised to see it run into 7-digits. The shipping costs would also be astronomical. Unless you are like bill gates, this would not be a personal endeavor. Best of luck.