The old saying - "if it looks too good to be true, it probably isn't" is the best description and advice when it comes to BP in the DC area
) I would stick to only those providers reviewed on here or the other popular board out here, and/or those listed on Date Check or p411. One final note - DC tends to be a popular location for visiting ladies, so you may need to see who is in town on the dates you will be here...
Good luck...