Reply To: Need advice for resource/custom price-fields set-up.

Yes that would need to be resources too if you need the whole functionality like availability check and complex price calculation for both.
If both get booked independently from the other it would really need to be that separated, but else you could let them book the tour first and after they’ve entered the CC details you could ask them if they want a accommodation too and lead to a page&form only for the accommodation where they don’t need to the CC details. I would add you a shortcode command to disable the payment process for that.