Foxbodies are still low price? Where? 3 gens are going below sticker where? Show me either one say under 20k miles.
73-87 Squarebodies will never be highly sought after?
Dude you can’t be serious or this really is your first rodeo.
I guess I remember my first time.
The average auction price of a 1987 GT Convertible is sitting around $15,000 right now. In comparison, the average price of a 1967 Mustang Convertible averages $41,000. 1997 Mustang GT Convertibles (low miles under 40k) average $30k, higher miles, $20k.
No matter the year or body type (well, we're not going to talk about the '77 Mustang Landau), the unused cars will fetch a super premium. Doesn't matter if it's a Mustang, Belvedere, New Yorker, Corvair, or any classic really. There is a niche buyer that is looking for a low mileage survivor car and they will pay a big premium for them. However, when you toss those out, the Fox Mustangs and the Mustang IIs are the bottom of the barrel in terms of Mustang desirability. They don't even hold up value when compared against an equally underwhelming SN95. As shown above, the '97 being only 10 years newer than the '87, and it sells for considerably more.
Once you squeak past the '71 Mustang, the only really sought after Mustangs in terms of high collector value are Shelbys, SVTs, and a few of the one-off models like the SVO, Cobra R (which is an SVT car really). There's a side market for Saleens and Roush cars... but Roush cars are kind of like the budget Shelby option and they don't generally do so well at auction. Even then, the 90s era non-Terminator, non-Mystichrome Cobras of that era aren't really all that desirable. They fetch a small premium above their GT counterparts, but they're not special.
But back on point... Fox Mustangs, by and large, are not highly sought after. I'd begin to say that with most collectors, they're simply undesirable. Beginner and amateur collectors might want one because their uncle had one when they were kids or some such... but the Fox Mustangs were underpowered, relatively ugly in comparison to most other Mustang generations, and were made of plastic and synthetic materials that do not age well. There's a term for a lot of Fox Mustangs: Auction fodder. Many people, me included, have sold a few Fox Mustangs at auction. We generally clean them up, swap the upholstery and put a stripe kit or something silly on them just to get them to pick up a few dollars across the block. The best I ever did was an '87 GT convertible that I purchased for $8,100. 82k miles. I spent around $800 on repairs and refreshing and sold it for $12,000. I cashed out a whopping total of $1,400 after auction fees and costs. The Fox Mustang shares the same fate as the square bird Thunderbirds... in that the market doesn't reward a restoration. A fully pristine restored Fox Mustang is going to cost $60k or more to do. They won't bring 50k at auction. Same with a '64 T-Bird. A concourse restored example might bring close to 50k if it's all numbers matching, etc. The cost to restore a '64 T-Bird, that was originally in decent condition, cost me close to $100,000 (I did a lot of it myself, but it was a present for my dad). It is appraised at $42,000. Fox Mustangs are eerily similar in that they're not worth it to restore, so everyone just restomods them.
The other thing about Fox auctions: The people bidding on them don't bring a lot of money, generally. They're the "classic" for people who can't afford to bid on a '69. So while you might get 20 people bidding on it, they're bidding in $100 and $50 denominations. If someone loses the auction, there's 20 more just like it, probably at that same auction. They're still everywhere. It's not like a '69 Mach 1 351c where a big auction might have 2 or 3 examples... one of which is going to be a big restomod.
Lastly, the other thing that's really hurt the Fox market is the drag racing scene. It's very difficult to find an unmolested Fox GT that hasn't been raced and cobbled together with all sorts of f'd up repairs. They were popular at the track when they were new, and they're still popular today. The cheap donor cars get scooped up for tubs and a big motor and continue on as a budget dragster. This leaves a fairly wide gulf between quality "collector" cars and the plethora of aging drag cars with their rusted frames, bent unibodies, and 2ft high of Bondo all along the rear quarters.
For these reasons, the Fox Mustangs are generally not desirable. Outside of the 15,000mi unmolested unicorn, most of them aren't worth the cost to maintain or store. Even if they're perfect, the average person sees one and goes, "Eww." I'm a long time Mustang guy, and I am one of those people. There's just no draw to a plain looking slab sided car with anemic horsepower. Back in the '90s when I was in my late teens and early 20s, I never could understand why people were buying them to take to the track. They used to go nuts over running 13s, and here I was in a 70 Torino 429 running high 10s... and I guarantee you I spent a lot less on my car than the new Mustangs cost.
The Fox Mustang is one of the few "classic" Mustangs that, when adjusted for inflation, trades well below its MSRP. It's just a very underwhelming car and the only people that buy them are very specific niche buyers. As of yet, supply is too high and those niche buyers have plenty of options, thus, the price on them is still very low.