Here is what I did. I owned 2 rideable geldings which I rode and showed. I ended up having to stop riding for a few years due to injury and ended up selling them both from lack of riding. From there I bought some babies Cobalt being one of the resulting ones.I knew I would have the time to work with a foal AND I know that by the time he would be of riding age that's when I was going to get back into the tack myself.
As it has been posted, if you know you will have the time, money and expertise to work with a foal then by any means I think it's the best way to go. There is not other bond between a horse and rider than one you will get with a foal you raise yourself. Be prepared for the amount of work it's going to take and patience. They can be a lot of fun but they can also test every bone in your body.
Cost wise, foals can be a lot more to raise than to buy a trained horse. You have to think of the board, training and all the vet and horse care you are going to be putting into getting that horse to the age and point of training where you can ride compared to the horse that is already good to go.
Hope it helped. Good luck