Deathcap is too damn expensive

In the 27 games of ranked I've played so far this season I've literally only purchased it once. We lost that game.

What reason is there to buy deathcap when there are cheaper alternatives that provide more useful passives? Consider Luden's Echo.

Current build: Morrellonomicon + Hourglass. About what you would expect for midgame, right?

AP: 200

Now let's compare what happens when we add Ludens and Deathcap as our third AP item.

Ludens AP: 300

Deathcap AP: 432

Wow, looks like I'll be doing way more damage, right? Wrong.

Looking at Luden's passive, with 300 AP it deals

400 + 120 magic damage (across 4 targets)

Now consider your full rotation of spells as a mage. Using Orianna as our example, she deals: Q: 50% AP W: 70% AP E: 30% AP R: 70%

Or 220% AP in a spell rotation burst. (she might also auto attack but the difference from autos won't be large)

Damage with deathcap: 950 x N

Damage with Echo: 660 ×N + 520 = 1180

Where we assume N is the number of champions Orianna hits with her full ult, and Echo will hit 4 people during her combo.

We can see that after two champions hit Orianna will deal more damage with deathcap than with Echo, but let's be realistic:

How often does Orianna hit every one of her rotation on more than one person? Two is fairly realistic.

So with Orianna if you buy Ludens Echo you can deal similar damage to two or less targets without Deathcap, but you'll get it 600 gold earlier, and have more movement speed which is important in creepyghosty meta.

So why bother with saving for deathcap if I can buy Ludens echo earlier and close out my game with just that item?

I don't. I buy Luden's Echo and close out the game before I even get a chance to build deathcap. It's just too expensive for the benefit, and as a mage every minute saved is a minute before their tank builds more MR. Moving around the map faster helps me push the lanes in and siege, and I can end the game without saving enough for deathcap.

Deathcap is just too expensive to justify delaying my my itemization to save for it.