Hello,
I bought a new brass portafilter for my Professional from partsguru sometime ago, which came with a double basket for only $66... A pretty competetive price when examined on paper. However, the quality of the portafilter is far below expectations. It has a very dull, pale yellow coating that is somehow darkened at the corners, and is very poorly lacquered. After less than 3 months of usage, the lacquer is already peeled from a lot of areas (which by the way is coming off black because of interaction with coffee and is very thick), mainly the rim, and there are some black dots because of espresso residues getting SOMEHOW under the loose lacquer... Very bad quality I would say but does the job nevertheless. The spout is also different with a round end, rather than the rectangular end found in the portafilter I had before, but this is no issue.
All in all, I suggest, since the portafilter is already very expensive, to pay more while being satisfied rather than paying less and feeling bad after all.
(Today is a sad day, in which I lost my single basket

)