Even when looking at the prices of Foderas (I have two and am a complete fan boy) we have it really easy compared to the cost of other (acoustic) instruments in the world. The fact that a professional level bass guitar can be had for a few hundred bucks would probably make some concert violinists weep.
Every time this thread topic comes up regarding Fodera, it is important to revisit the law of diminishing returns. Sure, the more expensive something is, the fewer "improvements" or "upgrades" over lesser priced instruments will be possible as you go on, but to someone, the mix and combination of those changes may be perfect for them and worth the extra money. To others, they might not even be improvements, as whatever the changes are, they might not mesh with that person's tastes or playing style. They don't have to be for everyone. One thing is certain though, that bass will sell, as will every other Fodera posted on their site. Something must be working.
The Porsche analogy is pretty accurate. You might be able to have just as much fun in a '99 Miata as you could in a new 911 Turbo, but that all depends on your approach to driving, how fast you want to go, who much it would affect the rest of your life as far as expenses go, etc.
I justified my used Fodera purchases in a very systematic way, and have no regrets, as after owning or playing just about any kind of bass that interests me, I know for a fact that i can do things on my Imperial 5 that i couldn't on any other instrument I've touched. I've also met the people who built it, find ti to be beautiful, and love the different sounds I can get out of it. For me that stuff matters and was worth some of the extra cost.
The rest of the justification comes from the fact that I see music purchases as a hobby, a passion, and also as my vice of choice...well, that and craft beer.
I have chosen not to have some of the expensive habits that friends of mine might have, and instead allow myself a yearly budget on music gear. I figured out what it would cost to smoke a pack of cigarettes a day for a year, divided that in half, and there it is. I generally allow myself 1500 or so a year in (new) gear purchases, so if i sell a bass for 500, I allow myself spend up to 2000 that year. It may seem crazy, but it has worked for me and I needed some way to rationalize it.
In the end, to each their own. There are tons of cool options for us to choose from, and not every one, no matter the price, will be right for everyone.
Cheers!