No because the "afford" bit has the sense of "poder", so "can" would be innessential to the whole meaning. And, should I say, not optional.
In "I will take a vacation when I can afford it." The verb can
is necessary because it is another can of worms altogheter, since it refers to the "I will take a vacation", so it´s a condition involved. That is "when I can afford it".
In ""10 Ways to afford your vacation" it is a "complete" sentence in meaning, it´s assumes that you will learn "how to" afford it. Whereas, with "when" you will need it.
Others certainly will expand this in a more linguistically-savvy terms.
The fact is, this is one of those topics that we hone with time and the experience with English.