The dictionary tells us that the verb "merecer" means "to deserve."
"I don't deserve something like this."
But songstress Julieta Venegas does not believe that living "deserves the pain" but rather that living "is worth it."
Es contigo, mi vida, con quien puedo sentir que merece la pena vivir.
It's with you, dear, with whom I can feel that life is worth living.
Captions 7-8, Julieta Venegas: El Presente
A few more examples:
Merece la pena estudiar.
Studying is worth it.
¿Merece la pena leer este libro?
Is it worth reading this book?
Merece la pena is synonymous, though perhaps a bit more formal and poetic, with its extremely common cousin, vale la pena. Our amigos in Mexico City demonstrate nicely:
Al igual que pues que tiene sus pros y sus contras y... pues aun así vale la pena. ¿OK?
At the same time it has it pros and cons and... well, even so it's still worth it. OK?
Caption 31, Amigos D.F.: Te Presento
The verb valer commonly means "to be worth."
Una imagen vale más que mil palabras.
A picture is worth more than a thousand words.
Also of note:
If you've ever been to Spain, you know that ¿Vale? (OK?) or Vale. (OK.) is slang that is thrown around a lot amongst Spaniards. ¿Vale?