I just checked, and my current longest-lived character has 567,174. And nothing to spend them on-- he not only has all the houses, but has all the magical trinkets and weapons and such that all the vendors sell.
That's part of why he's pretty much retired.....
With only a few exceptions, my characters share my obsessive need to sell every bit of loot they come across. They tend to learn how to cast Ease Burden and how to make feather potions early on. They don't really go out of their way to get loot-- that is, they rarely dungeon-dive
just to get stuff to sell-- but whenever they go into a dungeon, they kill everything and take everything and only keep the nicest and most useful pieces and sell the rest, no matter how many trips it takes. Except for mages, who buy a lot of restore health and restore magicka potions (they make a lot of them too, but the instant effect store-bought ones are much more useful in battle), my characters rarely buy anything other than houses and furniture and weapons and pieces of armor (I use a fair number of armor and weapon mods, and most of them are set up to sell the items through vendors for high prices). Very few of them pay for training in anything or for any vanilla weapons or armor or such.
They seem to generally have at least 10,000 to 20,000 septims through much of the game and buy houses and furniture when they can afford them. After the first few levels, they never even really think about money-- they just seem to always have enough.