I think this explains
beautifully what the OP is about.
Poppy xx
Exact-a-mundo Poppy . . .
To the OP, your Nigerian contact can not justify paying a large ammount into a bank account when the job cost is only a grand if they are indeed laundering money... which by the way, they are...
Greedy people atract scam artisist and you must never be arrogant as to what the sum £X,XXX.XX means to you relative to the person finally receiving it, you even get this difference between the North and South of Britain never mind Africa, Asia and Western Europe so be vigilant and understand relatively speaking why the scam artist is willing to go to so much trouble. The team you met are the well spoken English fluent 'hook' team to rope you in, all seems good but there are several levels of scam you could be targeted with despite precautions...
(1) Money laundering and the use of your name to buy contraband, guns etc via identity theft.
(2) The Standing Order / Direct Debit pinch, you sign a contract and they have your bank details, they launder the money and then transfer it straight back out. They have your signature remember...
(3) The Dinner Date, you go out for a meal and they watch you enter your PIN into the terminal, they have your bank details... bye bye money.
As to whether charging too much is a crime, well no but on a commercial level and for longevity of business it's never a wise move unless you are into one hit wonders and building a relationship upon trust and repeat custom is what builds a "business" rather than a "market stall" so that is your own decision. If you have a good service and it's worth the money the value is relative to whose gaining from it, a £10k website may make a company five times as much opposed to a £500 website which may just be a business card online so let those with the humph blow steam.
My advice is walk away from anything to do with Africa period because it's just not worth the hassle, simple as...