All things true but sometimes the mare really out produces herself or you have an older or injured mare who doesn’t move as well as she could (or a combination of both). Sometimes it can be quite misleading. Sometimes.
I also don’t know any breeders who have a business of selling foals that routinely invest 30k into getting the mare in foal. That type of business model would be disastrous. It’s one thing if breeders could justify the sales price for a foal for what it actually cost to breed but that just isn’t the case.
And on a separate note, all broodmares should be coveted and appreciated for reproducing whether that be live cover, AI, ICSI, etc. Just a simple ultrasound is not very fun for the mare. Carrying foals and getting into foal is a large undertaking for the mare and it’s one of the reasons I appreciate and have so much love and respect for broodmares. Blessed be the broodmares.