Etihad Airways Etihad Guest - Cheaper to cancel EY booking than change?

I have a booking with EY in April flying DUB to BNE return via AUH in Y class. I asked for a change to create a stopover in AUH for 3 days and was quoted ~850 EUR per person to change. I've checked the price for a new booking and the fare difference is ~50 EUR. My existing booking has a cancellation fee of 250 EUR per person. Are there any other risks involved in creating a new booking and cancelling the old?

Fare rules
Change your flight: Permitted at a charge of EUR125.
Cancel your flight: Before departure permitted at a charge of EUR175. After departure refunds are not permitted. Refund administration fee: Etihad charges service fees for all tickets being processed for a refund, in addition to any fare penalties applicable.

Not sure why I was quoted 250 per person to cancel.

That's probably the described service fee, which is on top of the penalty.