Yes, the 1848 Baby Dragoon was made during this period but the OP asked about Army Revolvers and although officers often bought their own small pistols I don't consider a .31 caliber pistol to be an official Army revolver.
I believe the book YANKEE ARMS MAKER by Jack Rohan, 1948 Harper & Brothers, USA, gives the answer to the OP.
In chapter 17 (pp 169-177) information about the year 1848 shows that Whitney backers stirred up Congress about the costs of the revolvers Colt sold the government for the "Mexican Contract".
"On March 28,1848, the Senate passed a resolution asking for information about the entire Colt business, and on April 13 President Polk sent it a brief message along with a report of the Secretary of War:
'To the Senate of the United States:
In answer to the resolution of the Senate of the 28th of March, 1848, I communicate herewith a report of the Secretary of War, transmitting a report of the head of the Ordnance Bureau, with the accompanying papers relative to the firearms invented by Samuel Colt. Such is the favorable opinion entertained of the value of this arm, particularly for a mounted corps, that the Secretary of War, as will be seen by his report, has contracted with Mr. Colt for two thousand of his pistols. He has offered to contract for an additional number at liberal prices, but the inventor is unwilling to furnish them at the prices named in his offer.
The invention for the construction of these arms being patented, the United States cannot manufacture them at the government armories without a previous purchase of the right to do so. The right to use this patent by the United States the inventor is unwilling to dispose at a price deemed reasonable.
James K. Polk'
On page 171, the chapter goes on to say:
"...As the controversy over his profits continued to rage, he (Colt) suddenly offered to make ten thousand revolvers with all accessories for $25 each. If he received a contract for a hundred thousand he would reduce the price even more, he informed the War Department..."
A bit of research I did indicates that $25 would be around $710 in today's dollars.