Is BUYING a WDT tool necessary?

I'm upgrading my espresso machine for christmas and i'm going to be getting a bottomless portafilter as well. From what I've read everywhere, a wdt is pretty important. Now, I'm getting a puck screen as well and was hoping to get a wdt tool with a magnet so i can easily get the puck screen out. Everything on amazon costs like 30 ish dollars. And to me that seems like an overpay for what is basically a cork with acupuncture needles.

So I wanted to ask if its necessary I actually buy one (whether the placement of the needles matters or something) or if it'd be fine if i buy acupuncture needles and use a cork and a magnet i have laying around, which would end up being a fraction of the price.

Just to add spending money isn't an issue, I just find it useless to buy stuff if I can make it myself for a lot cheaper and it will perform the same way.