Why not buy one decent pen “shell” and then just buy the plastic tube with the tip and the ink afterwards?
I know many companies use pens for marketing but still, they could apply this too and also stand up for the environment while still do marketing.
That, and the ink can handle a bit of water unlike that of a fountain pen (unless you use India ink but then good luck if you have a leak and ruin your bag or shirt because nothing can get that stuff out)
PS The last time I used a check was in the 90s 😆 Do people still use them where you are? I couldn’t even get one from my bank if I wanted to.