Like all good technical questions there is no right answer. And if you ask 10 makers who have a few years of experiences in your chosen hobby, chances are you will get at least 11 answers. So take the following for what it is, just some lesson learned from my personal .experiences. Things I wished I had known, could change or just didn’t have access to when I was just starting out.
So tool or parts? Here’s the pros and cons of both:
Parts: Parts are what make a project work. They tend be less expensive than tools and thus you might be tempted to buy a bunch of raw materials. However buying too many parts without a specific project in mind (like resistors and caps for us electronics nerds) might mean being left a bunch of parts to be misplaced, lost or just plain never needed. On the flipside, not having a small stash of spare parts can mean being one or two components from completing your project at 9pm on Thursday night. Now you have either wait until tomorrow or worse, order online and wait! This can lead to a loss of “mojo”. You laugh, but it does happen to the best of us. Then the project just sits…for weeks.
Tools: Tools are cool. When we use them we feel like Tony Stark. But they can be expensive (relative to parts) and some tools are more valuable when starting out, though may not be as sexy (take for example a digital multimeter versus an oscilloscope). DMMs are useful but the waveforms of an oscope are so darn cool. But again, given the expense, you may not be able to purchase as much depending on your budget.
So what’s a nerd to do? If possible, join a local makerspace for a few months and use their tools with your supplies to build a project. Learn what tools you actually use and which manufacturers/models your prefer. If makerspace is not possible, maybe you befriend someone who is a few years ahead of you in a mutually pursued hobby. See if they have recently upgraded from entry level tools and perhaps you can borrow the tools they now have relegated to workshop storage.
If a makerspace or a friend are not possible, then I would find a well documented project online (one that lays out the parts and tools used) that peaks your interest and duplicate their purchase. Chances are the tools will be handy across multiple projects. Also, double the part count so that you have other extras should you burn some parts (especially ICs, and trust me, you will) or best case, you will have some extras to start building a parts library.
Another thing to consider, there are things you will need that aren’t directly involved with making a project, think of them as the “cost-of-doing-business”. Storage bins, power strips, lighting, and ample horizontal workspace will be just as valuable, if not more so, than tools and parts. Be sure to invest in things that spruce up the utility of the workshop too.
Lastly, be prepared for change. You never stop learning and growing as a maker. The best makers tend to have broad and seemingly orthogonal interests that intersect in unique ways. For example, wearable electronics. If you told me 10 years ago I’d be sewing circuits. I’d laugh. But now I do. So the point is be prepared to acquire tools and parts that you would never have thought necessary. To do wearables, in addition to soldering irons, I needed to acquire conductive thread, needles, and fabric hoops, clear fingernail polish.
So there you have it. In my opinion, when starting out try to find ways to beg/borrow for the tools and put the money to project-specific components. Order extra parts to start building a spare parts library and keep it organized. Acquire (and upgrade) tools over time based on using actual tools and getting advice from people who also participate in your chosen hobby. Don’t forget those who come after you as well, pay it forward!