FWIW, I do the following for unknown persons:
- Require an email from a domain to verify ownership
- Only accept Paypal from verified accounts
- If domains are hidden behind privacy services, personally I am immediately skeptical of validity and absolutely require some form of verification. In 15 years in this business, it's been my experience that most people serious about business don't try to hide their business.
- Do a search here and Google, and other known resources, for the person's email, ICQ number, domain names, etc. It's usually not difficult to weed out the potential scams and avoid a hassle.
In other words, due diligence is a must to avoid scams. Once satisfied, I have no problem in paying for implementation beforehand. There's a
lot of very good people to do business with on GFY.