Inexpensive solution for catch-all emails

Here is yet another way. Use AWS SES to receive incoming email and to forward it. This AWS blog post describe how exactly it can be setup.

Depending on your email volume, it probably cost lower than what you are paying. Given that the services involved - SES, S3, Lambda and network traffic all have free tier. (The end of the above blog post also give some cost estimates)

This method will require some knowledge to setup or someone can help you do that.

Here is another alternative - Zoho Mail. It can do catch all and forwarding.

All the pricing plans are lower than your current subscription of 6,5EUR. (Note: They also have a free plan, but it does not support forwarding.)

There are domain registrar that provide the email catch all and forwarding service that is included in the domain registration fee or as an add on fee.

I assume you are now paying domain name registration fee (yearly) + GSuite fee (monthly). So it might lower your cost if you transfer your domain to such registrar. (Assuming you can/want to do that.)

If you provide your top-level domain (ie .com, .net, .eu, .de, ... etc), I may be able to suggest such a registrar.

[Update]

Came across this solution for .pl domain.

Gandi provide .pl domain and comes with "unlimited aliases and forwarding addresses". The .pl price is €20 per year. So it would come down to what you are paying for your domain now.