Does this one really require a horse? Ri'Dariit noticed taking quests will give gold enough, and if you not sacrifice craft items for research and sell instead, this one will receive more gold too. Cyrodiil gives you items for vending too very often, but this one has feeling that reason of OP is for horse is all the walking in battlefield. Have patience, you buy horse, then you buy all bank and backpack upgrades, what will raykay buy then? Faster you get everything faster game might loose point to play? Coin will not buy you happy!
Fusozay Var VarJaji kor nirni. Ri'Dariit ahnurr shir Gouranga an vasa rid-t'har.
I make a decent amount with skill points in cooking. If you forgo the bank upgrades and backpack upgrades which is silly high and just go on to find recipes and cook.
At this time I can feed two horses per day and enough left over for any repairs I may need during playing time. It starts slow but just vendoring the provisions gets me a nice little pocket of change.
If you are focus on a horse, then I say don't buy anything. Just cook, vendor, put points in cooking, cook some more, wash, rinse, and repeat.
If I had not listened to my wonderful fiancé I would be close to being able to getting the lowest costing horse (not counting my two 1 gold each horses), if I had not purchase backpack (bag) space.
You need to farm dungeon bosses now, before they nerf them.
Also depending on you level, find a good spot to AE kill lots of mobs and do this for a few hours.
While levelling do not repair you equipment, just replace it.