Once a car has passed 10 years old it's true value is what someone will pay for it. You are paying $7,000. for a 12-year-old car but one that has seen less miles in it's dozen years than most cars see in three years and by your account, the '93 is physically 'flawless'. That matters. So does the fact that the 'Fox' 5.0 Mustang is a
desired vehicle and - as they stopped making that model in '93 - not in plentiful suppy. In short, it's no Taurus. It's a 'niche' vehicle; one that has a special appeal for a small number of potential car buyers. We consider it special, if not yet 'collectible'. The same way the early ('64-66) Mustangs were in the mid 1970's.
If it's truly flawless, has 41,000 original miles and was well-maintained then it probably is worth the selling price - but only you can decide that. What someone else would pay is irrelevant. I might pay $9,000. for the same car so does that mean you got a bargain? Someone else might only pay $5,000. for the same exact Mustang. Does that mean you got shafted? Neither. If you want the car, are assured it's in the condition you expect and you can afford the price, then it's worth the money - to you.
As for the reliability of the '93 Mustang: it's fine. Especially with only 41,000 miles on it. They do squeak and have a few minor problems (water pumps fail, front brake pads wear fairly quickly due to weight distribution) - but allow me to assure you with some personal information.
My 1990 Mustang LX 5.0, which I bought new in March of 1990 (for $13,600.) has sat outside (in the northeast) for 15 years and now has 125,000 miles on it. It has been raced but not really abused. I change the oil and filter every 2,000 miles and have never missed a 'scheduled' oil change. My Mustang has most of it's original important mechanical parts. I changed out the rear differential gears, added frame connectors (recommended), an aftermarket shifter and a CAI unit - and that's about it. It's on it's second exhaust system, clutch, radiator , struts, shocks and rear brake shoes. Many tires and front brake pads have come and gone since 1990. It has the original T-5 transmission, the cylinder heads have never been off and I've installed only one new set of valve cover gaskets. The front end suspension is all original and solid. It's been practically trouble-free and a helluva lot of fun to drive. Yes, the Strawberry Red Metallic paint and red interior are faded and it has a few small rust spots and body dents, but it still looks good from a few feet away and takes a decent wax job. If your (potential) '93 Mustang is half as good it will give you years of driving enjoyment and ownship pleasure, as my 1990 LX has given me.
I wish you well.
