[zenobia43]

You can eliminate a few more combinations by using clues 2, 4, and 1.

From clue 2, we see that $1220 cannot be Red Admiral. Therefore, Lowell can never be Red Admiral.

Then from clue 4, since Red Admiral can no longer be Lowell, then $1200 cannot be Lowell either.

Now from clue 1, we know that Lowell has to be $10 less than Joel. At this point Lowell can only be $1210 or $1220, and Joel can only be $1220 or $1230.

Either Joel or Lowell has to be $1220.

That means that Trevor cannot be $1220.

Use clue 9 to put the Megathymidae in the $1220 slot. That forces the Adonis Blue up to the $1190 slot.

The rest of it cascades from there.

Hope that was right!