What kind of projects are you thinking about? Do you know any electronics?
has all kinds of chips that make it fairly easy to make a preamp, headphone amp, or low-to-medium power amplifier. But a lot of "modern" chips are surface mount with close-pitch pins make it difficult for hobbyists. ...You can still get a pretty-good selection of chips in DIP packages.
Speakers are the easiest thing to build. You don't necessarily have to do "furniture quality" woodwork or finishing. I cover most of my speakers with leather-look vinyl (like most guitar amps, except I usually use brown whereas most guitar amps are wrapped in black vinyl).
One time I built particle board speakers and then used a woodgrain kit to make it look like walnut.
Up to a point you can build a speaker more economically than you can buy one. When you get into high-end speakers you probably can't match what you can buy.
You do need some space for woodworking and it helps if you have a guide for your saw so you can make straight cuts. It's also helpful to have a jigsaw or router with a circle-cutting jig.
Or, some people use all kinds of things to easily make a speaker "cabinet"... A bucket, or barrel, or a pipe, or almost anything to control/contain the soundwaves from the back of the speaker.
You can find some good speaker kits but I don't know of any "good" (and complete) electronics kits. I remember seeing Heathkit amplifiers and they looked and functioned as good as anything you could buy but they have been out of business for a long time.
It seems like lot of people are building music streamers around the Raspberry Pi.
...I don't build anything electronic anymore unless it's something I can't buy. Most electronics is made on automated assembly lines with cheap labor, and very little labor. Any special-custom parts (like the case/cabinet and front panel) are also manufactured in quantities that allow better than DIY quality/appearance at lower than DIY cost.
And there are things you simply can't build yourself... You can build your own smart phone and I think you need a license before you can buy Dolby or DTS decoder chips or anything related to (copy protected) HDMI.