It depends on the model. There are over 200 air rifles on the market. You can find anything from a Daisy Red Ryder for around $35 to a Feinwerkbau that will cost you over $3000.
It all depends on who made the air rifle and the power plant that the rifle uses.
it all depends on the condition of the rifle.
in general 180 $ is the minimum for a reliable rifle.
What condition is it in..
Don't put as much air in the rifle. If you have a dial to set the power then use it. As you shot the power drops. You can dry fire some PCP air rifles.
An Air Rifle is either a BB rifle or a pellet rifle. It uses air or gas to propel the projectile.
I am a little confused by your question. Do you mean Webley air rifle. I know that Wembly makes scopes but I am unaware that they make air rifles. If you mean Webley then I need to know the condition and the model of the rifle to give an estimate of value.
A sporter air rifle and what?
No
To get an estimate of value you will have to state the condition of the rifle and give the SN#. There are 5 different series of this rifle.
50-200 USD
It all depends on the model and condition of the rifle.