Communication add-ons represent a significant hidden cost that can double your Intercom spend if not properly negotiated. Vendr's data shows SMS costs approximately $0.05 per message, bulk emails around $0.40 per 1,000 sends, and phone minutes at $0.12 each. For a moderate-volume team sending 10,000 emails monthly, you're looking at $4,800 additional annual costs. The real challenge is usage unpredictability. Many teams underestimate their communication volume, leading to surprise overages. Our analysis shows companies typically exceed initial estimates by 40-60%, turning a budgeted $5,000 annual add-on cost into $7,000-$8,000 actual spend. Negotiate volume tiers upfront rather than pay-per-use pricing. For email campaigns, committing to 100,000+ monthly sends can reduce costs by 30-40%. SMS pricing becomes more favorable with 5,000+ monthly message commitments. Most importantly, negotiate overage protection - we've seen companies secure 50% discounts on usage above committed levels, providing crucial budget predictability for growing communication needs.