Yes they come in both airsoft and pellet format.
See the link Below for Spring Pellet pistols and Airsoft pistols
most spring airsoft pistols cost about that... but if it's a used pistol than it should be about 10
if its spring pistol get a new spring or a better piston (if they even make upgraded pistons for pistols) if its gas i cant help you
Each spring pistols must be reloaded after each shot.
I assume you are asking about BB guns not Air soft guns. There are a few that fall under $50 but they are C02 not spring powered. Marksman makes a line of spring pistols under $50 but they are terrible and not worth the cost. See the link below for C02 air guns.
Minors can't purchase air pistols but they can use them. I wouldn't carry them around in public though.
the best ones are spring snipers because they tend to work better during spring season. Gas pistols can work good in Winter but be sure to fill your gun up using LG gas when they come to your house to fill your gas bottles!!
Varies by the pistol. Normaly better than spring.
There are too many types: airguns that are used in the auto industry, Air Rifles, Air pistols, Air soft guns.
Benjamin model EB22. Crosman model 2240. Benjamin Marauder Air or C02 Pistol. All 3 of these are .22 cal C02 air pistols, There are several others but they are spring or pneumatic not C02 systems
Yes, they shoot plastic 6mm bbs
possibly in quality by a little but not in performance.
If you take care of the gun it could last years and work good