@Ruby Ruiz
Good wholesalers are problem solvers for both parties; motivated sellers and investor buyers. They are deal finders and match makers.
For motivated sellers - they find motivated sellers that may have just been procrastinating their problems so long that they're in a really bad place. They may be so behind on taxes, mortgage payments and or the property can be severally distressed from deferred maintenance and have just been in denial about their position until some one reaches out and says that they may have solution. They can help the seller sell their problem property quickly to help them move on with their lives. Which can be a major relief for them and can lift a huge burden from them.
For investor buyers - they do all the grunt work pounding the pavement, marketing and talking to potential sellers in precarious positions and work out a great win win cash price that allows room for an investor to get a great deal on their buy and has room for a fee for the wholealers efforts. Many good investors are happy to pay this fee for the efforts of the deal finder. This is not an easy task, however with the right level of competencies and a lot of hustle and persistence a wholesaler can make some cash to hopefully invest in their on REI deals in the long run.
I believe good wholesalers will give you an accurate estimate of what they know the ARV to be and what they know the estimated repairs to be. However, it is always prudent for anyone buying any deal that they should do their own due diligence. Most wholealers are in a business of building a buyers list, so they are not intentionally out to screw over investors that may be potential repeat customers. Would you? Yes there may be a few inexperienced wholealers that get their numbers off, but any investor worth their salt knows to check their numbers. Remember there are wholealers of all property types and segments within the REI world. Wholesaling is also not even just in real estate either it is found in almost all industries. It's nothing new.
Although, not every wholesaler is good at what they do nor or are all ethical; this is also the case in most professions. No matter where you go and what you do you have to first protect yourself and do your due diligence.