Prebuilt maybe have some nice margin, but I don't know any gamers who haven't bought their PC custom, or assembled by the retailer. Those have very thin margins, both component manufacturers and retailers have very stiff competition.

At retail prices but I’ve never known anyone besides rich people or rich grandparents that can afford to spend $2500+ (video cards are well above $600 for high end and the other components at retail tend to get inflated similar to how Apple pads their SKUs around) so a teen can mess around playing games (mostly looking at it from the lens of how I was raised and the attitudes of my elders as well as my non-nerd friends). The usual ignorant gift giver would have bought a console or something towards the console like games or an online subscription.

The areas usually where margins come from are:

1. Skimping on PSU quality 2. Reduced motherboard features 3. Adding LEDs as a “value add” (why earlier this year RAM with LEDs we’re going on sale ahead of the non-LED RAM)

That depends a great deal on the part, and—again—what is "high" relative to other products. nVidia's Quadro cards have much higher margins than the models targeting gamers.