I have been here couple times and it is bang opposite to the arch. If you use economy parking which is at the mansion house around the block, you only pay $8/day as against $ 26 valet parking. We booked via priceline and hence it wasn't a bad deal. However the housekeeping was terrible. They cleaned zilch.
Breakfast buffet is $15 and change... you might be better of to to go to Hardees which is a block away.