Even 'a waste of money' is in the perception of the observer. If the purchaser doesn't feel she is wasting her money, then is it really a waste of her money if she wants it and has the money to spend, hobbyist or not?
Is it a waste of money for a hobbyist quilter to buy a quilting machine? Or a hobbyist weaver, to buy a huge standing loom? Or a private pilot to buy an airplane? I really don't think what we spend on our craft needs to be dependent on financial return.
Yes, some are quite costly, but I've seen some others that are really affordable (depending on one's financial situation, of course). Just as Kim mentiosn, several folks here at SMF have built their own soap cutters. Now and then a soapmaker will sell a cutter and you may find a bargain that way. OR, you might just be lucky to win one at a raffle (I did once.)
However, as a new soapmaker, I found that a simple mitre box and a dry wall knife will also do the trick. I used this for awhile before moving on to my first professionally made soap cutter:
Back when we could still go to in-person gatherings of total strangers in close proximity in closed rooms without masks and touch things without worry, I attended a soapmakers gathering that also included a swap where I bought my first wooden soap mold, silicon lined for pretty cheap. So that's another way for beginners to get affordable soap molds (again some day in the future.)