It may seem unreal, mainly because newgrounds is filled with a younger age group that thinks everything comes easy. Yeah, it's best to do things that interest you and can put a little money in your pocket. Someone asking for something free probably doesn't understand how time consuming drawing art for a game or whatever it is they want. Also could be that they are poor and have no money to begin with(which is pointless to reason with them). But someone offering to pay(note that it's an offer).
When you PM them you can come to a fair price, even if it's just alittle more than what was originally offered. It is better than nothing, you'll find that taking chances is alot more relieving than not trying at all. It does help I've experienced a few times that' it's better to see what you can possibly get then not trying at all, even if your comfortable with the price.