Determining value of browning Sweet Sixteen

Question
I have recently been surfing the Internet for an affordable Sweet Sixteen.  The prices I have seen range from $800 to over $2300.  I understand gun values depend on several factors.  Probably number one is its value to collectors, then manufacturer, then condition.  Today I saw an answer provided by Sid Lark a couple of years ago that valued this type of shotgun at between $400 to $700.  The sixteen gauge was never a real popular gauge in the first place.  Why the wide range of difference between Sid's estimate and what I am seeing on the Internet?

Answer
My refence says For the Browning Auto-5 standard weieght it says add 40% for 16 gauge and 20 gauge.
The 16 gauge was 2nd highest seller prior to 3 inch 20 gauge being introduced.
Not all auto-5 16 gauge are "Sweet 16" There were 3 production runs on them.
$200 to $1250 depending on condition on FN made guns.
add 25 percent for matte rib,  add 50& for vent rib.
For Japan made $150 to $1150 depending on condition.
The 50th Aniverary $250 to $1250 depending on condition.
Sid prices would typical of gun in Good condition 2 years ago.
You may want to look at.
16ga.com