You can obtain the Mossberg Plinkster for around $120, and you can order extra magazines and even 25 round magazines for that little rifle, which has an action based upon the same system in the Marlin Model 60. The value of the plinkster is the reloadable speed over the Marlin Model sixty tubular feed system. Of course, there is a tubular sotrage/reload system for the Marlin tube-fed rifle, which makes it possible to keep 120 rounds at the ready and nearly as quick to reload as a separate magazing system.
Yep, the Plinklster is a fine little rifle as well.
Dick's Sporting Goods usually has them on sale in the winter. I picked a up Model 702 for my boy two years ago for $89.
Spare 10 round magazines (made by Mossberg) are still only about $13 at Cheaper Than Dirt:
http://www.cheaperthandirt.com/13477-36.html
The Half-Pint Plinkster model 801 is a good looking great starter rifle for a youngster.
As NavyCanDo and jaydee770 point out, while a .22 might not be the first choice for defense it is still a deadly firearm. It can easi;ly disable an antagonist and even kill him/her with a well placed shot.
To me one of the best things about a .22 rifle is that you can target practice all day when cartridges are only 4 cents instead of 50 cents. Another is that they are just pure fun to shoot.