On the link, I think it drops the price by $1321 if you don’t need the accessories. So $3500 (give or take), less $1321 = $2200 (+/-) for engine without accessories.
I’ll be honest, I didn’t know that was even an option. If you were a real bargain hunter, you could probably piece together a Rotax with a new engine for a good price. That said, new accessories will definitely add up to more than $1321 if you buy them individually.