Howdy ntex.
A few things. Did a sign with the gun say 5.25" or was that your estimate? SAA's are generally 4.75", 5.5", and 7.5". Plus some shorter lengths called Shopkeepers, Sheriiff's, etc. Next, did you happen to note the serial number? This would make it easy to verify what year the gun was made. And did you happen to notice the caliber marked on the barrel? If the barrel was marked .44 Spcl then the gun would have had the barrel and cylinder replaced. If the gun was marked 44 w.c.f. (44-40) then the cylinder could have been replaced with a .44 Spcl cylinder but the bore would be kind of small for .44 Spcl. 44-40 barrels back then would have been sized .427. I am not positive what size early production .44 Spcl barrels were, but modern .44 Spcl. is .429. A soft lead bullet of .429 would probably shoot okay in a .427 barrel though. There is also the possibility that this gunshop knew nothing about SAA's and just called it .44 Spcl when it is actually 44 w.c.f.
As for value, a gun that old in 90% or better condition is highly likely to have been refinished at some point which definitely lowers the value. And the caliber change lowers it as well. On the other hand, if the caliber change and/or the refinish was done by Colt, then the value is much higher. You would need a Colt letter to verify that. I'm not knowledgeable enough to know what those values would be, but if the gun is actually a 44 Spcl and is in good shootable shape, I myself would probably buy it for $1100 as a shooter to go along with my 3rd gen .44 Spcl Colts.