Letter Bank

by Andrew Thomas and Seth Kleinerman

This puzzle combines two chestnuts involving the value of words: The idiom "Don't use a ten-dollar word when a nickel word will do", and the problem of finding words equal to a dollar, where A=$0.01, B=$0.02, etc.

So, in the across clues, there is an "expensive" synonym for the word provided which uses all of the letters of the "cheap" clue word, plus additional letters costing the dollar amount.
For example, HOT + $1.67 = PULCHRITUDINOUS.
Down clues involve a slight twist: as suggested by "keep the change", the "expensive" synonym uses all but one of the letters of the clue word.
For example, FIRE + $1.02 = CONFLAGRATION + E

Fill in the answers into the criss-cross grid, and then read the extra letters from the down clues in left-to-right order to spell PHONE US TO EXCHANGE WORDS. Upon calling us, solvers receive a message that our answer is worth $0.74, so they should call us back with their best word worth $0.74 to trade for it. When they do so, they receive the answer UPKEEP.

The clue answers are:
Across Down
APT + $0.98 = APPROPRIATE
AVER + $0.69 = ASSEVERATE
BAD + $1.03 = UNDESIRABLE
BIG + $0.99 = BROBDINGNAGIAN
CANT + $1.91 = SANCTIMONIOUSNESS
CRUEL + $0.63 = UNMERCIFUL
CUT + $0.93 = DISCONTINUED
DRY + $0.78 = ANHYDROUS
ELITE + $1.05 = INTELLIGENTSIA
END + $0.93 = DENOUEMENT
FEAR + $1.38 = FAINTHEARTEDNESS
HOT + $1.67 = PULCHRITUDINOUS
LIT + $0.79 = ILLUMINATED
MEANNESS + $1.40 = INCOMPASSIONATENESS
MUTE + $1.24 = UNCOMMUNICATIVE
NONSENSE + $1.19 = INCOMPREHENSIBLENESS
RAIN + $1.13 = PRECIPITATION
RARE + $1.3 = EXTRAORDINARY
RED + $0.65 = INCARNADINE
REST + $1.02 = INTERMISSION
RUIN + $0.86 = DESTRUCTION
SAD + $0.34 = DISMAL
SAD + $0.57 = DESOLATE
SIN + $1.36 = TRANSGRESSION
TOP + $0.68 = PARAMOUNT
TOP + $0.96 = OUTPERFORM
TRIP + $0.8 = PHANTASMAGORIA
TRIP + $0.84 = PERAMBULATION
TRIP + $0.88 = PEREGRINATION
  ANGER + $0.65 = INFURIATE + G
CLEAN + $0.77 = IMMACULATE + N
CON + $1.14 = HORNSWOGGLE + C
DECIDE + $0.53 = ADJUDICATE + E
EXTRA + $1.41 = SUPPLEMENTARY + X
FIRE + $1.02 = CONFLAGRATION + E
IDLE + $0.61 = LACKADAISICAL + E
OIL + $0.7 = LUBRICATE + O
OLD + $1.16 = ANTEDILUVIAN + O
PALE + $0.73 = ETIOLATED + P
POOR + $0.94 = IMPOVERISHED + O
PREDICT + $0.91 = PROGNOSTICATE + D
PURE + $0.92 = IRREPROACHABLE + U
RACILY + $0.87 = SALACIOUSLY + R
RESTORER + $1.92 = COUNTERREVOLUTIONARY + S
SHARP + $1 = PERSPICACIOUS + H
SHINE + $0.54 = LUMINESCE + H
SPARE + $1.15 = SUPERFLUOUS + A
SPLIT + $1.34 = COMPARTMENTALIZE + S
TOP + $0.18 = APOGEE + T
TURN + $1.03 = CIRCUMVOLUTE + N
WAN + $1.54 = EXSANGUINOUS + W

The filled grid is below:
                                                                               C                    
                                              ANHYDROUS                        O                    
                                              D                                U                    
                                      C       J                    E INCOMPREHENSIBLENESS           
                            I         O       U                    X M         T                    
                            M         M       D                    S P         E                    
                            M         P       I             C   PARAMOUNT      R                    
                   E        A         A       C             I      N V         R                    
                   T        C         R       A     H       R      G E         E                    
                   I        U         T   PHANTASMAGORIA    C    L U R         V                    
                   O        L         M       E     R       U    A I I       BROBDINGNAGIAN         
                   L        A         E             N DENOUEMENT C N S         L                    
                   APPROPRIATE      SANCTIMONIOUSNESS       V    K O H         U                    
                   T    E   E         T             W       O    A U E     FAINTHEARTEDNESS         
                   E    R             A ILLUMINATED O       L    D S D         I                    
          PULCHRITUDINOUS             L  U          G  L    U    A      OUTPERFORM                  
                        PEREGRINATION I  B          G  U DESTRUCTION       R   N                    
                        I         R   Z  R          L  M    E    S         O   A                    
                        C   UNDESIRABLE  I       UNMERCIFUL      I         G   R                    
                        A         E      C             N         C         N   Y                    
                        C A  INCOMPASSIONATENESS       EXTRAORDINARY     S O                        
              TRANSGRESSION    O  R      T             S       N L       A S                        
                        O T    N  O      E             C       F         L T                        
                        U E    F  A                    E       UNCOMMUNICATIVE                      
                        S DISMAL  C                       S    R         C C                        
                          I    A  H              S        U    I         I A                        
                          L    G  A              U        P    A     DISCONTINUED                   
                          U  PERAMBULATION       P       DESOLATE        U E                        
                          V    A  L         PRECIPITATION R    E         S                          
                          I    T  E              L        F              L                          
                       INCARNADINE      ASSEVERATE        L              Y                          
                          N    O        P        M        U                                         
                              INTERMISSION       E        O                                         
                                        G        N        U                                         
                                        E      INTELLIGENTSIA                                       
                                        E        A                                                  
                                                 R                                                  
                                                 Y