She said that she spent $6000 on renfest. buying fantasy clothes, jewelery, etc.
The third horse isn't bought yet. She showed a couple candidates on stream and said it's her birthday gift to herself. (Obviously the lifetime price of $2M is bullshit, that's like $5500 a month over 30 years. Her super exclusive boarding covering everything so she can just come in and ride is closer to $1k a month). And yeah, there is super expensive horses, depends on the breed, age, etc. - she said that her other two horses cost lik $25k and $40k or so.
It also makes total sense for a narcissist like Nick to let her make this show with the money on stream - 1) he can mock all the people who showed concern, 2) he can flex the money, expensive bag and phone, 3) he can wrap her up in a super fucked thing to do and have blackmail material against her for the future, 4) he can stroke his ego how much of a game of throneseque trickster he is.