Will not qualify for the loan without the anchor bolts/tiedowns unless the inspector misses the fact they are missing.
Unfortunately, the anchors have to be embedded in the concrete when it is poured - would be HARD to do after the fact and require a bunch of concrete jackhammering to expose the rebar and tie the anchors into the rebar, then repair the concrete, because just plain concrete anchors into a 4-6 inch thick slab would not be strong enough and would break up the concrete.
That could be done, but probably more expensive than the other options, so you are probably going to have to go with earth anchors and strapping - commonly around $1000-2500 depending on your seismic and wind loading area - more in areas with shallow bedrock that need drilling to install anchors or with very large units.
Here is an article with more info on the typical requirements (minimum standards vary by state and also if your trailer is in a FEMA flood or storm surge area):
https://www.nachi.org/manufactured-ho...
Your contractor would be a mobile home/manufacturer home installation firm - no Angies List category for that - only mobile home category they have is Remodeling - Mobile/Manufactured Homes, so that would be your starting point. Be sure to get the federal (FHA/GNMA/HUD/VA) form certifying to the foundation installation from the contractor. Usually this is issued after a design/inspection by a civil engineering firm - though some installer firms are also approved to issue the certification.
Rereading your question, sounds like you are the BUYER - so talk to your realtor about having a pre-sale inspection done then putting in a contingency requirement that the OWNER have proper tiedowns installed (and be sure to specify if over-the-top or exterior exposed ones are unacceptable to you) and cetification provided by him as required by HUD/VA/FHA. Then the $ uncertainly is not your concern - just make it a condition of the sale, to be done by the owner.
