The idea is for there to be more training point quests and more ways to get training points.
As you level up there are plenty of training points available and most max wizards have spare training points sitting there unused. My max life has 25 unused training points and she has every spell she wants/needs. My storm has 22 unused and still has at least 8 training point quests to complete.
By level 50 you have 19 training points available By level 100 you have 46 training points available By level 120 you have 54 training points available
It can be hard to stretch them in lower levels but the balance of having to decide keeps it challenging. It could be too much too soon if we can get feint and tower and perhaps a second school as well all very early on. I love that KI introduced the member benefit of free training point buy back because a lot of us don't realise the value of them when we start out. I'd like for there to be a warning to use them wisely...I made some very unwise decisions early on and it cost me a lot to fix as the member benefit didn't exist yet.
If you're wanting/needing more training points the best way to access them is leveling up. There are lots of quests available from Prospector Zeke, Eloise Merryweather, Ogden Peake, Inyanga Whitestripes, Francis lux and Zaltanna the Mirrormask. Treasure cards can be a lot of fun and useful too if you can't yet afford to buy the spells you like to use.