I don't think you overpaid but you didn't get a great deal either. I think if you are planning on making him and integral part of your team and build around him it is fine to pay above market. But if you are just planning on making a profit on him it's a bit of a gamble.
I recently splurged 2.8 million on a player because he was the most skilled 19 year old I've ever seen. I bought him to make him a key player on my team in the future rather than to try to sell him for a profit, but I think I could make a million or two by next season if I wanted to sell him. I envision him as Scottie Pippen type player, someone who can do a bit of everything and who is a defensive monster at the SF spot. I hope to get him to 17 outside defense and 12 inside defense along with petty good passing and rebounding. He'll be the perfect Robin to my Batman Nemesio Xermade. Here are his curent stats, he should pop in inside shot this week and maybe jump shot as well:
Owner: Eclypze
Weekly salary: $ 10 040
DMI: 20900
Age: 19
Height: 6'8" / 203 cm
Potential: allstar
Game Shape: mediocre
Jump Shot: average Jump Range: respectable
Outside Def.: sensational Handling: strong
Driving: average Passing: strong
Inside Shot: proficient Inside Def.: prominent
Rebounding: average Shot Blocking: respectable
Stamina: average Free Throw: average
Experience: awful
Yeah I agree I didn't get a great deal, but I don't think I overpaid. I plan on keeping him for a long time and making my team around him which is why I paid so much. I would have loved to have paid less, but he was bid up to 3 million dollars so nothing I could do about it.
As for your player, very very nice. Would be nice if his JS/JR/Rebounding were a bit higher, but there will be plenty of time later to improve that. I also love the stamina and free throw, they are a pain to train!