If you can find sportmix dog food close to ya, the 24/20 is very similar to blackgold. Blackgold for me the last time I got it was $27 a bag and heard about sportmix on here so I started feeding it for $19-$21 and they look as good as when the were on blackgold but if those 3 are your choices I'd have to go with the black gold, 3 cups for 50lb curs and 4 cups pits 80-90 lbs is what i fed and they looked better then when i fed 6 cups of diamond.
sportsmix 24/20 and the dogs look good with less feed.
