The quality of the pickup will differ. A cheap one won't necessarily have the quality of the expensive ones, using a steel needle Vs a diamond needle or the like. There's also the problem of cheaper units having arms that aren't balanced properly. And incorrectly balanced arm can wear your vinyl, which is a problem if you're playing "originals". If you're playing some mass produced modern stuff that you can replace you may not care.

My cheapy unit has a "heavy" head putting around 7grams of weight on the records.

That may not be an issue for you.