These are a bit of guesses since I have a large pony in the US, but some costs are the same (and this assumes you are buying the kind of equipment that you’re generally expected to have at the higher levels, obviously you can do it successfully for less and of course you could do it for a LOT more)
Cart - I’d budget about 6k, a friend of mine showed her mini up through intermediate and had a really nice cart that was safe on Marathon but also suitable for presentation. At least with a mini you don’t need a carriage, never mind two!
Harness - approx 1k for marathon, 2k for leather presentation, more of you use a true collar.
gear for you and your equine (vest, boots, helmet, bonnets, whips, gloves, stuff): 500-1k
Presentation outfit: $100 to the sky’s the limit. This really depends on how serious you are, but a really nice apron and hat can be about $700. And then you could - as we all do - need several aprons, hats and jackets. But there’s a lot of reasonably priced options available as well.
All that stuff you forgot about or didn’t know you needed until you saw it (harness racks, an assortment of driving bits which tend to not be cheap, special reins, pads for the harness, etc) - $500
The good news is you don’t need all this stuff at once and you don’t necessarily need all of it, like a presentation harness (aka a fancy leather harness). You should definitely invest in a top of the line marathon harness like yonies, IVC, Camptown or a high end zilco, because a) it’s your life and b) they look more than nice enough in dressage. Ditto for a good helmet and vest, but there’s a huge range in price one those as well. And if your plan is to move up, you really want a good 2 wheeler that’s suitable for marathon, that has a lot of stability but is still nice in dressage. After that everything else can be upgraded (for instance, xan still uses woof boots on marathon. One day I’ll get the Mr. $$$$tockings because they are awesome, but woof boots do the job).
As for fees, I generally budget $1000 per event, but those are full 5 day events*, and that is entry fees, stabling and camper hook up shavings and sometimes a paddock. I think entry and stabling are generally around 500-600. I haven’t done a 2 day trial in a while, but probably 350-500 ish for entries/stabling.
- Once you hit intermediate or higher CDE, dressage is on Thursday, lower levels are on Friday. The joy of having all day Friday to focus on marathon is offset by the extra day cost of camping, hotel, etc.