There is a romantic idea in the fountain-pen world that your first proper pen should be a real investment — a milestone object you commit to. It is a lovely notion and, for a beginner, usually a mistake. You do not yet know what you like, an expensive pen does not write better in the ways that matter at the start, and a modest pen teaches you everything you need to make the eventual splurge a good one.
Why you can't yet choose well
Choosing a pen well requires knowing your own preferences: what nib width suits your hand, whether you like a wet or dry writer, what weight and size feel right over a long session, whether you even enjoy the daily ritual enough to justify a serious pen. None of that is knowable in advance. A beginner buying an expensive pen is betting real money on preferences they have not formed, and the odds of buying the wrong expensive pen are high.
What the cheap pen teaches
It teaches you your preferences at low stakes. You learn whether you like a finer or broader nib, a lighter or heavier pen, by actually using one, and you do it without anxiety about scratching or losing something precious. You also learn whether the hobby is for you at all before committing serious money. By the time you outgrow it, you will know exactly what to look for in a real pen — which is the whole point.
The path that works
Start with a well-regarded inexpensive pen, write with it daily, and pay attention to what you wish were different — that wish list is your spec for the next one. Then, when you buy something special, buy it knowing your hand, your taste, and your commitment. The expensive pen is far more rewarding as a reward than as an entry ticket, and the cheap pen is how you earn the knowledge to choose it.