Those plastics don't only get inside you, but also into water sources. We can't estimate the impact exactly, and most probably your Aeropress contributes insignificantly.

Still, if you have money, there are worse ways to spend it than upgrading your plastic appliances. If you don't want to, no shame in continuing using things you got used to. But I invite you to keep in mind that consumers' habits might contribute to global issues.

As for me, I use a $1 cheap Cezve from Caucasus, and it just works. No need for filters, too.