I think you need to ask yourself what your end goal is? Eventing or climbing the levels and being competitive nationally?
Coming from a H/J background I find eventing very affordable but I do the LL and have zero aspirations past that. I wasn’t born wealthy-I just manage costs and try to keep in mind what is actually important to me and what is just keeping up with the Joneses. My husband and I do very well for ourselves, and while we spend a lot on my horses, we also are not willing to sacrifice long term planning and financial security to win a blue ribbon.
Looking at your list-I have two very nice horses-one cost us $5000 (way overpriced but he was an emotional buy-I had leased him for 10 years and the owners refused to sell him to me at 19 for $1) and the other was free off the track. Both very nice, maybe not UL material, but my older guy was very competitive in our area, qualified for area champs and AECs multiple times. He lost to the big money imports but we did that in the hunter world too so such is life. My younger guy isn’t the fanciest but lord he is fun and tough at the same time so I’ve really learned how to ride bringing him along. He is the ultimate adult ammie horse that I truly think will be an training level packer in the future and while he is never going to run FEI levels, he is exactly what fits my life right now.
My husband would be more willing to spend more on a been there done that horse, but for me, while it can be very frustrating at times, I have never had a horse that had experience before so why start now?
UGUS treatments-well that for me was a one time cost in both of my horses and careful management helps prevent that from being a repeated cost (I also keep my horses at home so this is doable). I own one custom saddle I got this year but for many years I did all 3 phases in a pancake flat hunter saddle and did quite well. So, not needed. Training and competing are variable, but for me, lessons are monthly fixed costs we work into our budget. I do not compete year-round so we save through the winter to pay for my April-Oct show season. I also judge locally and use that towards things like my custom saddle or entry fees.
I do find myself asking how people afford to import horses and go to FL for months on end but I also remind myself that most of the horse people I know make very poor decisions when it comes to money.
So my point is, I think it is very doable to event for reasonable costs if you are realistic about goals and not concerned with having all the things.