How to determine sales price?

[Sergio Rios]

With a site-built home I can ask a realtor for comps to determine a possible sales price.
how do I determine a sales price with a MH? 
What I’ve gathered:

If it’s owner finance you can just basically pick whatever number you want as there is no appraisal involved. You basically just choose a price and hope it works. That just doesn’t seem logical. 

I can buy a MH for $5,000 and list it for $1,000,000 but I doubt anyone would bite.