Yes
A new Glock 22 typically runs about $500. A used Glock 22 in excellent shape can range from $350 to $600. Everything really depends on the generation it is, condition (which should be perfectly fine, i mean it is a glock), if it has any extras, and if it is police issue or not. I would say a police issue in good shape would probably be worth $500-$600 easy.
See link below to GLOCK 22
A Glock 20 (third generation) will retail for about $600 in good condition.
Glocktalk.com or you can call Glock
No, they are different calibers. A Glock 17 is 9mm and a Glock 23 is .40 S&W. A Glock 22 magazine would fit in a Glock 23.
Contact Glock and they will send you a manual for free. You can also download one from the Glock webiste.
The Glock 22 (full size .40 S&W) and the Glock 17 (full size 9mm Para) have the same external dimensions, and any holster will be interchangeable between the two.
You'll need to be more specific - there are 5 pistol models that use .40 S&W rounds. They are: -Glock 22 -Glock 23 -Glock 24 -Glock 27 -Glock 35
Police most often use the 9mm Glock 17 or the .40 S&W Glock 22. The glock 17 magazine holds 17 rounds (+1 in the chamber), while the Glock 22 holds 15(+1).
FBI and US Marshals issue Glock 22.
No. The 357 SIG magazine will not fit in a 40 caliber Glock such as the model 22.