...Hotel Armstrong .. 36 rue de la croix st. simon, 75020 Paris
or
Hotel Nation Montmartre .. 4 Rue Boissieu, 75018 Paris

On a tight Budget Need help please??

"They are both on the other side of Paris. If you don't arrive too late take the RER, which will leave you at least much closer to them.

Here is a map of Paris, so that you know where the arrondissement are. The last two digits on the postcode. Porte Maillot is on the left, at the place called palais des congres. The number in soft dark grey is the district (arrondissement)
http://www.serurier.com/carte-paris.gif

Gare du Nord is in the 10th arrondissement."
(chosen answer)