My typical show costs (costs paid to the horse show, not my trainer) for a hunter at WEC Ohio are $1,000 - $1,200 per week excluding prize money. This includes entry fees for pro and amateur divisions, a hunter derby, a classic, stall fee, stall splits, shavings, hay, and a bunch of fees (office, USEF/USHJA, medic, schooling, night watch, etc).
Yes, definitely get a paddock. Worth every penny. I don’t recall how much the paddocks were at Ocala. We split them and they were on our show bills.
And definitely budget for photos. 
USEF offers a 15% discount on Hertz rental cars, although in Orlando there’s an abundance of inexpensive car rental companies.
I usually fly Southwest to Orlando. The fares are reasonable and if you have to change your flight, they don’t charge a change fee.
I usually share a hotel with a barn buddy, which will save lots of $$$.
Your barn/trainer costs will vary, based on the pricing model your trainer uses. For example, we pay flat day fees for show/training/lesson days or hacking/days off days. (BTW, I’m at a full service barn.). So I hesitate to ballpark those costs for you. We’re also charged for things like meds, hoof-packing, and expense splits. The more clients, the lower cost per client.
Braiding varies, but I’ve been paying around $50-$60 per mane and $30ish per tail…somewhere in that neighborhood.
Have fun!
