Support the claim made on page 274 of The Lightning Thief: "There is no such thing as a free lunch." Cite three examples from the book and include...

When Annabeth says that "'There's no such thing as a free lunch,'" what she means is that nothing good comes without a price or that one cannot get something for nothing.  One always has to pay, in some way, for any gift one receives. 

For example, Percy has always been considered a "troubled kid" who bounces around from school to school, always getting poor grades.  He's had to deal with dyslexia and ADHD, and these have affected his studies and made him think he is only capable of earning Cs and Ds at best.  However, Percy's dyslexia is only the result of his eyes being conditioned to read ancient Greek, and his ADHD is the result of his fighting reflexes.  The feelings of shame that have come with his struggles is the price he's had to pay for his ability to control water, and so on.  He can't just "lead a normal life" as he advises readers to do on the first page.  "Being a half-blood is dangerous.  It's scary.  Most of the time it gets you killed in painful, nasty ways."  So, while there are tremendous benefits to being a demigod, there is a price to pay for it as well.

Further when Percy gets to Camp Half-blood, it will mean safety for him; however, his mother, Sally Jackson, must sacrifice herself to the Minotaur in order to make sure that Percy and Grover are able to reach safety.  So, danger for her means safety for him.  They have to pay dearly in that they are separated from one another and do not know if they will ever be reunited, just to achieve safety for Percy.

Moreover, Sally Jackson has long sought to procure safety for her son, and this is why she married the horrible and malodorous Gabe, a terrible and abusive man: because his awful scent conceals Percy's.  As Grover tells him,

"'Your stepfather smells so repulsively human he could mask the presence of any demigod [....].  Gabe has been covering your scent for years. If you hadn't lived with him every summer, you probably would've been found by monsters a long time ago. Your mom stayed with him to protect you.'" 

So, Percy has been protected by his stepfather's repulsive smell, and having to live with Gabe's smell and abuse is the price that he and his mother have had to pay for security.