Yea seems weird that $3360 is not even divisible by 159.95.

Do you have other products that are logging revenues? Could that revenue be including other product sales accidentally?

I also wonder if this revenue reporting was working correctly before, or just recently implemented?

Even though 3360 / 159.95 does not work out, if 159.95 was rounded up to 160, then it would be saying you sold 21 units.

Also- you say two sites, are they reporting separately or into the same account? Or is this exact same number incorrectly appearing on two different sites and GA accounts?