Bitrix24 vs Zoho – Help needed

Zoho professional costs around $25 per user per month but Bitrix24 costs ~$2 for per userper month for standard plan?! Want to understand what the catch is – from anyone who has used Bitrix Standard or Professional versions — and also which tool works best for a 10-20 user organization with sales CRM needs. And anyone who has used both tools as well– which would you prefer n why?