I don't know how robust the plastic mould for your machine will be, I have had issues with plastic parts breaking on Philips kitchen appliances (always outside of warranty, naturally), so I can't really comment on that. However, depending on the type of pasta you intend to extrude may have a bearing on your choice. The bronze dies were traditionally used for the harder "higher quality" durum semolina pasta that has much more "tooth bite", hence using metal rather than plastic due to the stresses involved. Nowadays, manufacturers use Teflon dies as they are cheaper, but this results in a smooth pasta.
If you are intending on making dense pasta such as penne or conchiglie, semolina flour and a bronze die would be a good choice. If you are looking to make a finer pasta such as vermicelli or spaghetti, the use of 00 flour and a plastic mould would probably be fine.
I would also consider the amount of use the pasta maker will be exposed to. If you are only occasionally going to be making fresh pasta, a brass mould is probably overkill. If you are going to be making penne regularly with semolina rather than 00 flour, the bronze die is probably a better long term investment.
https://www.epicurious.com/ingredients/what-is-bronze-cut-pasta-and-is-it-worth-it-article
https://fabulouspasta.com/guide/best-pasta-flour/