Unlike everyone else, I was not content to just sit on my mountain of gold, and saw fit to bling out my horse as well.
Psh, the correct answer to "what should I do with this mountain of gold" should never be "sit on it". When in doubt, you should begin to augment your inventory with everything listed on the "things you can buy chart", utilizing bags of holding (or handy haversacks if you can get them) to augment yourself. A 13 STR character in pathfinder can carry something like 1,200lbs (or 120 cubic feet) of crap without breaking light encumbrance while not having to worry about attacks of opportunities when retrieving anything! (An 18 STR character could carry double that).
And if you really wanted to be prepared you'd take about 200lbs of
that and use it to store empty haversacks that you could take out and fill in the event of a carrying space emergency at the cost of a ENC penalty (you couldn't put them back till you emptied them, but you could store them while empty in the basic rules). An 18 STR character willing to go all of the way to heavy loading could hypothetically chop up an adult elephant into 2 ft^3 and 8 ft^3 chunks and carry it with them while still being able to move. 2 such characters could do the same to and adult dragon.
And only for the low, low cost of 120k gp per 18 STR character! That's only a little over 1/8th of your starting gold as a level 20 character!