i have two quarters, an american samoa and northern mariana island. are they worth keeping? they are in great condition, but circulated. just a few small scratches under a 10x
They're relatively common these days. Even though these two have a substantially lower mintages than the 50 state quarters, they are very readily available for pristine conditions for face value. I've been saving the "America the Beautiful" quarters, those are a more difficult find. Found my first Vicksburg over the weekend.
Even though 2009 saw the lowest mintages in decades, it is best to collect only the uncirculated ones as far as value is concerned. Coin collecting is different for each person. Some people collect type sets and the 50 state/territories/national parks quarters provide a large base upon which you can build a Washington quarter type set that is extremely affordable.
I'd hang on to the Northern Marina Islands one but that's just because I rarely find one. I think I'm up to 3 or 4 now total. I have all 50 states in MS and I'm pretty much hoarding the America the Beautiful coins because I like the designs.