To sum up Ray's (very good) points-- everything boils down to managing expectations. If a guy is good at that, he can find success in this hobby reasonably easily and without a huge outlay of time and money. Some sad souls among us cannot (or will not) live with the kind of car that is easily built. They're too slow. They don't handle especially well. They are the antithesis of waterproof. They require no small amount of care and feeding.
Whacking any one of the moles means another one pops up in another place. Want to be faster? Your already sketchy brakes will need a serious improvement. Want to handle better? Your ride will likely go south when you stiffen things up. Want to be low-'n-mean? You're going to scrape a lot of driveways. Want to be dry in a thunderstorm? Oh boy... get out your checkbook.
The cycle keeps escalating until before you know it, you're looking at a twin-plug, dry-sumped 2.3L motor with more handmade parts than off-the-shelf stuff. Or a turbo Subaru, or a 6-cyl Porsche engine, or a 3L Raby Type 4.
At the end of the day, there is a secret sauce-- but that sauce is different for every guy, because every guy has his own set of acceptable compromises. A realistic assessment of who you are, and what you can live, along with how extensive your budget and skill-set actually are will go a long way towards finding long-term happiness behind the wheel of one of these death-traps.
That's my story, and I'm sticking with it. Your mileage may vary.