My Fiero experience has been pretty positive and looks relatively inexpensive through my rose coloured glasses.
I bought my '84 SE 4 speed new & have over 365,000 kilometers (226,800 miles) on it now.
Purchase & all maintenance costs are less than $0.07 per kilometer or $70 per month.
For it's 30th birthday I treated it to a new condition dash & seats from a pick & pull.
It's a daily driver except in wet salty winter weather.
The paint is a little thin on the roof, but it just keeps going... It's fun because it still works!
In 2008 I was looking for a spare in case the '84 breaks down & it takes me a while to fix it.
I ended up finding an '88 Formula 5 speed with 5,200 kilometers (3,200 miles) on it.
Much better than a 'barn find' - it was a 'showroom find'!
I usually have it out a couple of times a week - it's the one I usually take to car shows as well.
I've put 20,000 kilometers (12,500 miles) on it. Beautiful 'new' car! It's fun because it's like new!
In 2011, I found the project I was looking for - an $800 '86 coupe 2.5L 5 speed with 107,000 kilometers (66,500 miles).
I've put '88 wheels, new tires, 'new' condition seats, many miscellaneous parts & an '87 2.5L engine in.
It shares daily driver duties with the '84. It's fun because I fixed it up myself & I like the 5 speed.
So I have one well worn original, one worn in mid-life model & one of the last, hardly worn!
I have regular plates ($90/year each) and regular insurance (average $600/year each) so I can drive them without any restrictions.
I figure the total costs are less than what a single new vehicle every few years would cost in depreciation alone.
I've had several of those as well - have to have something to drive in the wet salty snowy winter weather!
(Also to carry the family of 6...)
All that said, I wouldn't keep Fieros that don't get driven. I don't see their value skyrocketing...