What you actually pay for rental SaaS

Subscription prices never hurt in isolation. Add the quarterly statements and most hosts are surprised.

A rough table (5 units, PL, 2026)

Job	Typical SaaS	Free-ish stand-in
Channel / iCal sync	150–400 PLN/mo	merge script + cron
Lock codes from bookings	100–250 PLN/mo	Home Assistant + a small script
Guest message inbox	80–200 PLN/mo	FreeScout + Telegram bot
Cleaner scheduling	100–200 PLN/mo	shared iCal + chat
Profit reports	150–300 PLN/mo	Metabase on your own data

SaaS total: 580–1350 PLN/mo. Yearly: 7–16k PLN. That’s real money for tools that, once configured, don’t need someone else’s cloud.

The honest “but”

Open source is free of license fees, not free of work:

1. Someone has to set it up — hours, once.
2. Someone has to keep it alive — hours per month, not days.
3. Docs are often English-only.

Rule of thumb: automate the stable processes (calendars, codes, alerts) with open source; pay for SaaS where support and uptime are the product (e.g. a channel manager at 10+ channels).

Three numbers before the next checkout

1. Hours/month the manual process costs you now
2. SaaS cost per year, tax included
3. Months until setup hours would pay for themselves on open source

If (3) is under twelve, look harder at the free stack.