Pull a lot of engine out of main.asm

engine/items/tm_prices.asm

@@ -0,0 +1,23 @@
+GetMachinePrice: ; 7bf86 (1e:7f86)
+	ld a, [$cf91]
+	sub TM_01
+	ret c
+	ld d, a
+	ld hl, TechnicalMachinePrices ; $7fa7
+	srl a
+	ld c, a
+	ld b, 0
+	add hl, bc
+	ld a, [hl]
+	srl d
+	jr nc, .asm_7bf9d
+	swap a
+.asm_7bf9d
+	and $f0
+	ld [H_DOWNARROWBLINKCNT2], a ; $ff8c
+	xor a
+	ld [H_DOWNARROWBLINKCNT1], a ; $ff8b
+	ld [$ff8d], a
+	ret
+
+INCLUDE "data/tm_prices.asm"