I have a chance to buy one, has 300 miles and is titled in Arizona.
Anyone have any experience with these kit cars?

Its a new 5.0 Ford engine. I believe other than the headers its mostly stock. 5 speed and he is finishing the paint job now.

End of the day somewhere around $39,000 and I have to pick it up 5 hours from here.

It was a long time ago, but yes. I owned a MKI roadster for about 6+ years. It started life as a 302 with a 2.73 rear end and stock Mustang suspension. By time it was done it was a worked 351W with 3.73 rear and modified rear suspension and Flaming River steering rack. Holy hell did I love that car and would kill to have another. It was as raw of a driving experience as you can get. Loud, rough riding, windy, sometimes smelly...and I loved every second of it. Thing was fast as all get out...mine was about 350hp and weighed in at 2250lbs. With a short wheelbase, you have to be very careful with that power. Obviously, it has very limited use capability. Bad weather, etc... I did drive mine in the cold, I had a 12V blanket I would just wrap around me and wear a hat. As far as build quality, that depends on the builder obviously. Mine was rock solid. I blew the 302, but that was on the racetrack, so that's my fault. The rest of it was very good. What I liked most about the car was the community. Cobra people are AWESOME. My wife (at the time) and I started the local Cobra club and put on a yearly show. We would have 50 Cobras show up and it was incredible.

If you can do it, do it!! I'm so much looking forward to having another. Thanks...now you've sent me hunting, LOL.

Thanks
These cars are all over the place in price. I do not want a 427 as it just seems to be too much motor for street driving.
I have been looking for a 302 car but this one just popped up and its not far from me.

I had a Fiero GT with a 350 bored 60 over and some nice internals. Lowered so I can relate. But the Fiero just doesn't work out and the Cobra is less hassle.
Build quality, parts wise the kit was well done, I do not know who the original builder was. The current owner got the car and painted it but would rather have something that is less computerized.
We will see how things work out.

I have more than enough savings to get it and still have enough to survive a couple of years should the economy tank.
Not getting any younger and I miss tinkering and my DD is not something I want to keep putting money into as its reliable and we know how that goes.

Yes, prices for them are (and always have been) all over the place. That's because the cars are so unique and customized, even when compared to each other. Different manufactures...and even within the same manufacturer, the builder can chose from a nearly endless variety of combinations of engine set ups, transmission, rear end, suspension, interior, etc...basically when you buy a kit you're buying a blank canvas.

I drove and rode in a bunch of Cobras in my years in the community. In my opinion, anything over 400ish hp is going to go to "waste" unless you have a true drag racing set up. I had a friend who had a fully built big block with a blower on it. One of those things that stuck out 2' from the hood. No dyno in his area had capacity to hold it, but they estimated hp at around 1100. He took me for a ride in it and it was utterly silly. He sold it a short time later, saying it was too much for street use...it overheated easily. On the other end of the spectrum, when I first got my Cobra it was nearly stock from a Fox body Mustang GT. Engine, trans, rear. Don't get me wrong, it was fast. However, in the realm of Cobras, it was a dog. The 351W with mild work and a 3.73 rear was the sweet spot in my opinion. Fast as hell, but still 100% streetable.

If you get one, make sure to drive through a tunnel. Then turn around and go back through. Rinse and repeat. Hearing the sidepipes echo off the walls is intoxicating.