Yes, Browning has made them.
100-300 USD
Not sure what you describe as "Century". The only semi-automatic produced by Browning at the time was the Auto-5. Based on condition of your gun, look it up at the link below.
A shotgun.
The last 2 letters in your serial number NZ indicate that your Browning 325 in 20 gauge was made for browning in the year 1991.
The Browning Auto-5 came in 12-, 16- and 20-gauge varieties.
Download a manual from Browning or take it to a gunsmith
Citori, 20 gauge, superlight and upland models
2003; you will have to call Browning for model
1960.
1000 USD
No
Never heard of a model 22 BPS. A Browning BPS in 20 gauge can vary from 150-400 depending on condition.