The 12 cans of Spam costs $3 x 12 = $<<3*12=36>>36.
The total amount of 3 jars of peanut butter is $5 x 3 = $<<5*3=15>>15.
And the total amount of the 4 loaves of bread is $2 x 4 = $<<2*4=8>>8.
Therefore the total amount he will have to pay is $36 + $15 + $8 = $<<36+15+8=59>>59.
#### 59