Index and Match Function

You need to lock cell

Formula:

=INDEX(Rates,MATCH(TRIM($C13),hotel,0),MATCH(D12,Stay,1))

With -1 you'll get #N/A.
With 0 also if no match.

1 or omitted
 
MATCH finds the largest value that is less than or equal to lookup_value. The values in the lookup_array argument must be placed in ascending order, for example: ...-2, -1, 0, 1, 2, ..., A-Z, FALSE, TRUE.
 

0
 
MATCH finds the first value that is exactly equal to lookup_value. The values in the lookup_array argument can be in any order.
 

-1
 
MATCH finds the smallest value that is greater than or equal tolookup_value. The values in the lookup_array argument must be placed in descending order, for example: TRUE, FALSE, Z-A, ...2, 1, 0, -1, -2, ..., and so on.