Ouch!!! LOL But I guess in time; I'll be earning more gold as I level up. Never seem to have enough bank space.
And yes! You can increase your bag size by purchasing oats for your horse. So far, I've purchased 2 bag upgrades (1st: 400 gold and 2nd: 2000 gold) for all my active toons. Since the next bag upgrade of 10 slots is 5900 gold; the one slot you get from the 250 oat purchase is much more economical. Of course, this takes longer as you can only purchase 1 slot a day; but with the 2 upgrades and daily oat purchases, I usually have sufficient bag space. There are times I hit the inventory limit and didn't want to run to a town so . . . thank heavens for the add on Mail Return. I know many will not do add ons; but this has made my questing life much easier! I can quickly dump much of my loot into a "bounce" mail and continue on with questing. I also use it to "send" specific items to my other alts to either deconsruct or research. Truly, the mail bot return add on has been a life savior for me. You can find a variety of useful addons on the www.esoui.com website.
I have a question though. Are the bag upgrades in addition to the slots purchased from the stable?