Start with your channel mix, not the feature list
The single decision that determines which help desk fits is where your customers actually contact you. If 80% of volume is email, a shared-inbox tool like Help Scout or Front will feel faster and cost less than a full ticketing suite. If you run live chat inside a product, Intercom's messenger is the reason to buy it. If you answer on email, chat, phone, WhatsApp and a public help center at once, that is Zendesk's home ground and the others will require stitching.
Price per agent is only half the bill
Help desk pricing looks simple and rarely is. Watch for: AI resolutions billed per conversation on top of seats, light/collaborator seats that may or may not be included, help center article limits, and the tier at which analytics stops being a static dashboard. Model your real agent count at the tier that has your must-have feature, then add expected AI usage — that number, not the headline seat price, is what you are comparing.
Treat AI deflection claims as a hypothesis
Every vendor in this category now quotes a resolution rate. Those numbers are achievable, but they assume documentation you may not have written yet. The honest sequence is: publish your top 30 answers first, then measure deflection on your own content. Buy the AI tier once your help center can actually feed it — not before.
Migration is the real switching cost
Tickets, macros, help center articles, SLAs and integrations all have to move. Budget two to six weeks for a mid-sized migration and insist on a sandbox. The teams that regret a help desk purchase in our review data almost never cite features; they cite a rushed cutover that lost historical context.