Which phenom are you looking at? Is it a Phenom or a Phenom II and is it a 2, 3, 4, or 6 core processor? There are lots of options, phenom is not specific. Also which i3 are you looking at they come in a large variety of speeds and prices
Actually ,my hardware knowledge is in basics,that I won't know the difference between them.
And the market doesn't offer any varieties except for Intel ,that you can choose just 5 or 6 models of AMD if they exists !!So basically AMD stuff are 75% higher in price than Intel!
I will look for the available ,and will get back.