Depends on EXACTLY what you have. Range could be from 100-10000 USD.
The colt 1911 fires .45ACP ammunition.
Both can refer to 45ACP. 45 alone can also refer to 45 Colt
Colt Combat Elite (45ACP) $1000.00 Colt Delta Elite (10mm) $1000.00 (not out yet)
100-1000 usd
If you mean the standard Caliber of a 1911 model colt pistol,then this was chambered in the caliber .45ACP.
Either 1984 or 1995 according to Colt's site. A call to Colt at 1-800-962-COLT can reveal the exact date of manufacture.
You must call Colt. SN goes beyond published data.
45 long colt is more powerful. It is usually used in revolvers and lever action rifles.
100-700 USD or so
If chambered in 45ACP
According to proofhouse.com,about 48 years old. Made in 1961
Made in 1960.