But a board will always have some type of identifiable branding, which would directly go against this notion of him saying on parkerspov.com that he "can't afford fancy new skateboards." Not to mention, making his own just adds to that traditional trait of Parker being good with his hands and innovative. And, if you skate, you know that you can go through those pretty quickly so making his own boards in my opinion fits in line with the character's background...the costume stuff you just have to kind of looked past.
Plus, as you said it makes life easier on you because now you, like Parker, can just make your own boards for your cosplay! You might have to look up a few formulas though.