Tom can buy 1000/2=<<1000/2=500>>500 for half price.
He will spend $.50/2= $<<.50/2=.25>>.25 on the half-priced bricks.
Thus, he will spend 500*$.25=$<<500*.25=125>>125 on the half-priced bricks.
He will spend 500*$.50=$<<500*.50=250>>250 on the full-priced bricks.
Thus, he will spend $125+$250=$<<125+250=375>>375 total.
#### 375