I did a couple of quick plumbing jobs today and the value of having the right tool really was apparent. The weird yellow thing on top is a thing you shove down a drain and it snags whatever's down there clogging things up. If your tolerance for "yuck" is high, it will clear a drain in about 5 seconds. If your tolerance is not high, you probably don't want to clear a drain anyway.
The bottom thing is a core puller for Moen faucets. Last year I replaced a core on the kitchen faucet without a puller, it took me about 90 minutes and I wound up basically recreating a crude puller out of threaded rod and random tools, a block of wood and a pry bar. This time I spent $12 and pulled the core out in about 2 minutes. This one was more stubborn than the last and I'm pretty sure I would never have been able to get it out without the right tool. As a result the house water was only off for about 10 minutes.
Get the right tool, you'll save time and possibly money.