Assuming you aren't joking:
If someone wants to participate, I guess that's their right, but I sure wouldn't. You are planning on taking in $75 to give out about $24 in chips and $3 in postage...max? Gee, can I do the next raffle? I have kids to feed too, lol. When I started reading, I thought you were doing something for the Building Fund. If that's the case, I guess it sounds like a good idea.

MAYBE if everybody except the big prize winner received a $1 chip - then it might sound alright. At least you get something for your $5. Or make the big prize a Friday the 14th. Then it might be interesting. I just can't see donating $5 to an individual for a 6.67% chance at a $20 chip. Maybe it's just me. Maybe it's because I don't need that one?