This list is Mobile Home Specific.

1. Polybutylene Plumbing 

2. Federal Pacific Stab Lok Electric Panels

3. Tears in the underbelly + loose or missing underside Insulation

4. Missing or broken ground fault circuit interrupter outlets

5. Bad seals on double pane windows and sliding glass doors

6. Chips in the Skirting (usually caused by weed wackers). 

7. Leaking skylights

8. Soft floors - usually found near a leak

9. Dead smoke detector batteries

10. Inoperable HVAC systems

11. Rotted decking boards

12. Bad Roof

There you have it, the Top 10 + 2 list of items that wreck deals for Sellers or give a Buyer more bargaining power when buying a mobile home at the beach.

Many Sellers believe that when they list their house and someone makes an offer and they accept it that the deal is done, unfortunately (for the Seller) that’s rarely the case. Usually the Buyer orders a Home Inspection. A Buyer can then use the list of “Major Defects” discovered by the inspector to further negotiate the price down or request that all the major defects be repaired. 

If you are a Seller, it pays to have your home pre-inspected so you can find out what's wrong with your house and get it fixed beforehand. Otherwise you may get an unwanted surprise when the buyer has the home inspected and comes at you with a lengthy list of items they want repaired prior to settlement. 

Read on to see what these repairs typically cost

Polybutylene Plumbing - Cost to replace $2500 to $3500
Materials aren't very expensive but the Labor can be. 
Best replacement? Pex Plumbing kit on Amazon:

Federal Pacific Stab Lok Electric Panels - Cost to replace $1500 to $2500

Tears in the underbelly + loose or missing underside Insulation - Cost to repair $500 to $2000

Missing or broken ground fault circuit interrupter outlets - About $15 per outlet if you do it yourself or $75 to $150 per outlet if you pay a pro.
About $15 on Amazon.

Bad seals on double pane windows and sliding glass doors - $300 per window $1000 to $1500 per sliding glass door.

Chips in the Skirting (usually caused by weed wackers). $200 to $1500 depending on if just a few panels need to be replaced or the entire house needs new skirting.

Leaking skylights - Price depends on if the entire roof is bad or just a small area around the skylight. $150 for a small patch job to $9000 or more for a new roof and new skylights.

Soft floors - usually found near a leak. Repair price depends on how much of the floor is bad $150 to $5000

Dead smoke detector batteries - The least expensive of the bunch $1 per detector.

Inoperable HVAC systems - This is a pricy one at $5000 to $9000

Rotted decking boards - Depends on the extent of the damage. $150 for a few boards, $1500 to $5000 to replace a large deck. 

Bad Roof - This typically depends on the size of the roof but can range from a low of around $5000 to a high of around $12,000