A few thoughts-

1. You can't afford either at level 1 (probably not level 2 either).
2. Buying magical armor costs 1000+ armor costs. So essentially, you're paying 1,000 for a +1.
3. For someone actually looking to invest in armor, Full Plate is pretty cheap in the long run.


Honestly... I can't imagine ever using Half-Plate, unless I picked it up at a low level off an enemy and REALLY needed that extra AC. I'd certainly never waste my money on it. Full Plate is better in every respect but cost, and it isn't all that much higher in price. You'd be able to afford it by level 3 (2,700 gold), definitely by level 4 (5,400 gold).