Agreed, when I was at 7/16" and decided to go all the way up to 1 1/4" I knew I'd be doing a lot of stretching, and waiting to heal, and stretching and more waiting to heal. So in between I just bought the cheap $10 pairs of acrylic plugs and for quite a while just used one pair and in the process of stretching just kept wrapping ptfe tape around it to make it larger rather than buying new plugs. Once you get up into the larger sizes it's easier to just use the tape wrapping method than buying new tapers and plugs for each size.
Once you get to a size you plan to stay at for a while then it's worth it to invest in good quality plugs. I'm currently awaiting some custom carved obsidian stone tear dropsShould finally have them in another week or two.