In my opinion , its a bad deal , you can buy vivitar , soligor everytime , everywhere very cheap. I think their quality might be faraway lower than Nikon. Why you need 3 low quality , similar lens and a east german praktica ? It nuts , service the fg and be happy.
Its like giving a ferrari and buying 3 same model , same color Fiat plus a Truant. Dont do it.

Good luck ,

Umut