99% of the times we prefer to get an absolutely free solution rather than a very similar cheap one.
But...99% of the times, the cheap solution has something, even a very very little detail that is going to save you something - it could be money, it could be time or even energy.
So it's absolutely free really absolutely free?
It's your choice: save money upfront getting an absolutely free product/service or try to understand why the apparently same product isn't free. If you choose the first one, try to foresee what would happen if any of the pieces it's made of would broke, write it on a piece of paper and ask yourself again if the cheapest solution is worth the money.
If still it's not - go and invent it or get the free one.