I'm fairly certain they have basically the same ingredients - what counts in a primer is dimethicone.
Something interesting I found about primers. These are some popular brand's ingredients:
Smashbox<O
</O
Cyclomethicone,
Dimethicone Crosspolymer, Isopropylparaben, Retinyl Palmitate, Tocopheryl Acetate, Ascorbic Acid, Carthamus Tinctorium (Safflower) Seed Oil, Vitis Vinifera (Grape) Seed Extract, Cola Acuminata Seed Extract, Propylene Glycol, Camellia Oleifera Leaf Extract, Isobutylparaben, Butylparaben, Water.<O
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<O
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Vincent longo<O
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Water,
Dimethicone, Dipropylene Glycol, PEG-8,
Copolyol Crossopolymer, Phenyl Dimethicone, Sodium PCA, Dipotassium Glycyrrhizate, Pryridoxine HCA, Bistort (Polyonum Bistorta) Extract, Butylene Glycol, Sodium Citrate, Methylparaben, Methycellulose, Tocopherol.<O
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<O
</O
DHC Velvet Skin Coat<O
</O
<O
> </O
>cyclopentasiloxane
, dimethicone, dimethicone/vinyl
dimethicone crosspolymer, HDI / trimethylol hexyllactone crosspolymer, olea europaea (olive) fruit oil, silica, propylparaben<O
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<O
</O
<O
The ingredients in the primer I use:</O
<O
Cyclopentasiloxane;
Dimethicone;
Dimethicone/Vinyl Dimethicone; Crosspolymer; Silica; Tocopheryl Acetate; Trisiloxane</O
<O
<O
I like mine because it costs $6 for 1.5 ounce and it has fewer ingredients to mess with my skin and I can get it at CVS, Wal*Mart, or Walgreens.</O