How to test email spam scores with amavis?

I'd like a way to test a spam message to see its spam scores that SpamAssassin gives it. The SA db files (bayes_toks, etc) reside in /var/lib/amavis/.spamassassin. I've been testing emails by doing this:

sudo su amavis -c 'spamassassin -t msgfile'

Though this yields some strange results, such as:

Content analysis details:   (3.7 points, 5.0 required)

 pts rule name              description
---- ---------------------- --------------------------------------------------
 3.5 BAYES_99               BODY: Bayes spam probability is 99 to 100%
                            [score: 1.0000]
-0.0 NO_RELAYS              Informational: message was not relayed via SMTP
 0.0 LONG_TERM_PRICE        BODY: LONG_TERM_PRICE
 0.2 BAYES_999              BODY: Bayes spam probability is 99.9 to 100%
                            [score: 1.0000]
-0.0 NO_RECEIVED            Informational: message has no Received headers

0.2 is an awfully low scores for BAYES_999! But this is the first time I've used amavis, previously I've always just used spamassassin directly as a content filter in postfix, but apparently running amavis/spamassassin is more efficient.

So, with amavis in the picture, how can I run a test on a message to see its spam score breakdown?

Another email I ran a test on got this result:

 2.0 BAYES_80               BODY: Bayes spam probability is 80 to 95%
                        [score: 0.8487]

Doesn't make sense, that BAYES_80 can yield a higher score than BAYES_999. Help!