But it's not enterprise SaaS, is it? It's just a time tracking and invoicing tool. And it's not the only SaaS they will need?

Companies with 25 employees generally don't have money to pay a dozen SaaS vendors $2k each every month.

Maybe certain niche products that are critical to the business might be worth that much. But a time tracking & invoicing tool? Definitely not. Source: am actively moving away from Harvest due to this ridiculous price hike.