Changing a rental property price

[Ryan MacDonald]

Hello,

I have a question about adjusting the price for a rental property.  If I have a rental listed at $650/month and have two people interested but now want to increase the rent to $700 to bring it up to market value, are there any legal issues with doing so if 2 potential tenants are interested in the property?  Can I go back to them and say that I need to raise the rent on the price or do I need to honor that $650 price in order to avoid any legal recourse? 

Thanks,
Ryan