It would be worth around $55 in Excellent condition.
25-100 USD
It was rated at 480 FPS (More like 450 FPS in real life) in 1974
Let my examine your question. I think you mean Pellet rifle not Pellet gun. The Hy Score model 806 is the same model as the Winchester 422 and the Diana model 22. Unfortunately you did not give me any information about the condition of the rifle itself. Is it in {POOR, FAIR, GOOD, VERY GOOD or EXCELLENT Condition. You have to give me some sort of rating before I can give you an estimate of value. Tell me about the condition of the rifle. Does it still shoot?
20-220 USD or so
We've seen that model offered for sale online recently between $80-$120 without ANY play whatsoever. A more realistic price in my opinion is $50. The gun is very very simplistic and plain. Between 1969 and 1973 they imported somewhat less than 20,000 air rifles to be sold under the Winchester brand. The 422 was at the low end of the price line, and values today remain under $100. sales@countrygunsmith.net
These model 422 models range in price from 95 dollars for a gun with 60% original finish up to 190 dollars for a fine example with 98% original finish remaining.
Sometime around the mid 1970's. New information 7/10/2014 The Hy Score model 806 is the same model as the Diana model 22 and the Winchester model 422. They were made between 1953 to 1985
The smith and wesson model 422 was introduced in 1987 and was discontinued in 1997.
The stainless 2206 is worth about $285 in good condition. It is more sought after than the blued model 422 or the alloy 622.
200 dollars
You need the help of a gunmsith