-しかないもの

[mella]

あたし達はいつも金力で戦うしかないもの。
We cannot fight always as we'd like (at full strenght).
I have some problem to understand the ending of the sentece, but I think I understood the general meaning.

[Ongakuka]

I think you misread 金力 as 全力

I think you understand しかない right? It just means nothing (ない) but (しか), "We always have no choice but to fight with money" kind of thing

もの ending a sentence usually implies a kind of emphasis and explanation to the situation, or acknowledgement of the situation. I'm sure somebody else can explain far better than me. It also turns up a lot in the more colloquial もん form. And, as with this sentence, it is a device often used by women.