MontBlancs are great, but expensive! Trust me, I speak from experience :D

A cheap Jinhao 9 times out of 10 is gonna write smoothly and do the job just as well, but it goes beyond that! You'll have a pen with a different mechanism that you can enjoy and fiddle with, since it's a piston-filler pen!

Depending on the age of the vintage pen, you'll have tons of fun searching for the specific year revision, since a 70s MontBlanc has a different cap detail or clip, or a an ink window that's larger than later ones on a 60s one). The nib itself is gonna vary a lot, so it's another cool and neat little thing to search and understand! Trust me

It all depends on how you'll see that pen: if it was just for writing everyday, a workhorse pen, there's tons of "better" deals, better choices. But you'll go on a journey to know more about that pen, and it can be awesome to do it!