First of all, sorry if it's a simple and common question, but I'm really new to OW.

Starting points: via Marriott Rewards I got a few 120K miles on AA.
1) I get lost because the AA web page with the award just moved around.
(thanks to FT to help me finding it again thelink about AA OW Award , and yes, I use the search)
2) I see the cost and
class zone8 zone9 zone10
-eco- 120K 140K 160K
-biz- 150K 190K 220K
-1st- 230K 280K 330K

I see that first is basically double than economy, but biz is not in the middle point of this range but more to the lower part. Nothing to complain but... having accumulated basically all my point without flying (not all but the very biggest part) I'm quite surprised. It looks too nice to be true.
Is the OW 'average' business class so similar to Economy to require just 35% more points ? Or no avaialbility ? Or...
I have an other 120K miles and I'm feeling worried about placing them on AA.

Thanks for any feedback.