Moksha is the highest value.
One should do the duties of his station of life without any self-seeking. This is practicing dharma with indifference to sin or merit, riches or poverty, pleasure or pain.
Nishkama Dharma alone can break the cycle of life and death and supersede merit and sin, and lead to salvation in the absolute.
Both pain and pleasure are transitory, one following the other in a casual cycle driven by persisting desire. Of the two – happiness gained by effort driven by desire and happiness gained by forsaking desire – the latter is preferable because it frees man from cycle of pleasure and pain.