My understanding is that enterprise purchasing teams are often evaluated based on their ability to secure discounts compared to the initial sticker price of the software. Therefore, having a firm sticker price might make them less incentivized to purchase your SaaS. I suspect many companies don't put pricing up front so the email can say "Normally, we charge X per seat, but we'll give you a special volume offer of Y"

It's a part of the enterprise dance, sure, but I wouldn't say they become deincentivized to purchase if you say no to discounts or negotiations, at least up to p99.