You have learned a lot for 3 seasons. Do not forget to read some tutorials on forum, they are useful for everyone.
Well, "do not judge book by its cover".
You are very close to the point, but...
Experienced player usually do not buy players whose age is 30+ because later it is very hard to sell them.
I'm focused on 2 type of players on market, I choose them rather by value (and price on auctions) than by age only;
1) fast trainers - very expensive players whose age is 18-20, growth is very fast, that is why they are good on long term
2) cheap players - players which have slow growth, but good quallity. You can also find age 20 players which are very cheap due their very slow growth. They usually play 1-2 seasons in my team before selling. I buy such players in order to save money for fast trainers.
For example, on level 10 fast trainer costs ~30M while cheap player could be found ~10M
Good luck, have fun!
