Are there animal species in which the females expend more energy attracting males than in their offspring?
The reason why, in most species, males are competing to access females and females are choosy is due to Bateman's principle. 


  Bateman suggested that, since males are capable of producing millions of sperm cells with little effort, while females invest much higher levels of energy in order to nurture a relatively small number of eggs, the female plays a significantly larger role in their offspring's reproductive success. Bateman’s paradigm thus views females as the limiting factor of parental investment, over which males will compete in order to copulate successfully.


But there are exceptions to this general rule.

Fish

In many fish species (e.g. pipefish, scissortail sergeant and seahorses), males are choosy and females are competing. In these species, females deposit their eggs in a special brooding pouch that the male possesses. The male then has the energy cost of raising the offspring, while the female does not provide any parental care. As a result, males in these species must choose among competiting females for mates( Vincent et al., 1992)

Birds

In many bird species, there is bi-parental care, leading to competition among mates in both species. See the interesting case of Jacana jacana (Emlen and Wrege, 2004).

Frogs

In poison-arrow frogs (Dendrobates auratus), the male spend more energy for raising the offspring than the females and the males are therefore choosy (Wells, 1978). 



Related: Why are female not competitive for reproduction like males?