Modular homes must be fixed to a foundation like a house to a "sill plate". The financing would be different as it would be a real estate transaction involving the land whereas a mobile home not affixed to a parcel is known as a chattel loan (personal property only).
Modulars are not used for any park applications to my knowledge.
The cost is about 15% higher on the invoice is my experience. Singlewide modular housing is not something I would get involved with. Seems altogether weird to me.