Didn't somebody come out with a digital back for the F5? That would and did give some great film bodies a new life. As well as some of the best glass made. I've been out of the camera market for many years now.The only times I've had buyer's remorse was when I spent too little money.
I spent over $3500 for my Nikon F5 back when I couldn't afford it. It was the best 35mm SLR in the world when I bought it, even though it's probably worth $100 today, if that. I still have no remorse. Just holding that tank of a camera in my hand, knowing how perfectly it performs every task I ask of it, and how many wonderful events it helped me document, fills my heart with joy.
OTOH, I've bought second best a couple of times because I couldn't justify in my mind the several hundred extra dollars to get that last little bit of performance. In those cases, I've sometimes regretted it.
The lesson I take from all this? Don't settle and you don't get buyer's remorse.