Alternative to Kayako (help desk)?

Question

Helpdesk

Since the license for the 25-person kayako I love costs $7,500 a year, which is too much for me, I am looking for an alternative. Either free or significantly cheaper (budget up to $ 500 per year based on 25 employees).
From what I liked so far - OTRS, but rather weak after Kayako and the statistics look very strange.

Answer 1

Perhaps it will come in handy for someone in life, I answer to myself:
1) Jira + Service desk = $20 per year, hosted soultion
2) https://www.zendesk.com/product/pricing/
$12 per year
3) https ://www.zoho.com/support/pricing.html
has a free plan
4) helprace.com/pricing
has a free plan