The general advice from SE is to just flag spam as spam. This is especially true if the post if from a new, 1-rep user with no non-spam posts -- chances are it really is a spammer. Flagging as spam helps to expedite the removal of the post and also provides feedback to certain automated spam-prevention systems.
But in your case you found answers that seemed ok except for the spam link, and everybody was new and 1-rep at some time so maybe these are reasonable users who need a little guidance. Thank you for trying to help by preserving the possibly-useful parts of the content instead of just blowing it all away. In the two specific cases that I noticed, though, I ended up deleting the posts anyway, and here's why:
It turned out that the non-spam parts of the posts were plagiarized. One seems to be copied all over the net (the top five or six Google results were other copies of that exact text). How did I find the plagiarism? I pasted the first paragraph of the answer into Google to see what would turn up.
Tacking spam onto an otherwise-ok post seems to be a newer spammer tactic. It also seems that they don't feel obligated to actually write that otherwise-ok post themselves.
So when you see something like this, please either just flag as spam (it is, after all) or check for plagiarism before making a saving edit. If the post does seem to be the poster's own work, and if it's actually an answer per the Help Center, then editing out the spam and leaving a comment explaining why seems like a reasonable response. Otherwise, best to leave the post as-is and flag.
For people who can see deleted posts, here are the two cases that prompted this post:
(Ooh, consecutive user numbers -- just noticed that. Spam sometimes comes in waves like that.)