Creating a golem from scratch versus buying a manual

[Drakir2010]

Can this be right?
If I want to create a clay golem, I have to have the craft construct feat and spend 21,500 (per the bestiary).
OR
I could buy a manual (12,000) and construct the body (1,500) for a total of 13,500.

Flesh golem
by feat: 10,500
by manual: 8,500 = 8,000 (manual) + 500 (body)

Iron golem
by feat: 80,000
by manual: 45,000 = 35,000 (manual) + 10,000 (body)

Stone golem:
by feat: 55,000
by manual: 27,000 = 22,000 (manual) + 5,000 (body)

Stone shield guardian
by feat: 100,000 = 55,000 (stone) + 25,000 (premium) + 20,000 (amulet)
by manual: 69,000 = 44,000 (manual) + 5,000 (body) + 20,000 (amulet)

Now if I had the Craft Wondrous Item feat and all the appropriate spells available to me, I can cut the costs of the manuals in half yet again!

I suspect that I'm misreading these passages:

PRD wrote:

A golem manual contains information, incantations, and magical power that help a character to craft a golem.

The cost of the book does not include the cost of constructing the golem's body.

I want to say that the second sentence isn't meant to say "the cost of the book includes all costs except constructing the golem's body", but then why call out the body as not covered? If the intention was to still have the constructor pay the full construction costs, why isn't the language more explicit. Something like: "The constructor still needs to pay all costs associated with constructing the golem, including assembling the body" would be much clearer.

Is it really cheaper to buy a manual than to build your own? Please, someone help me justify this in my own mind.

[hogarth]

My understanding is that, yes, it's cheaper to use a manual -- even one you crafted yourself. It's a bit weird, all right. Note that you used to save even more money in 3.5 (although it cost you a bit more XP to craft the manual than to craft the golem).

[Mighty Squash]

It does pretty much make the craft construct feat pretty useless, at least if your plan is to make golem.

[Jorda75]

This is of course assuming you can walk into your local magic shop and say, "Yeah I'll taaaake, one Clay Golem Manual...two Iron Golems and...do you have the new Stone Shield Guardian in? Yeah toss in one of those."

Depends on your world, DM and context, but yeah, it's cheaper with books.

[Benly]

Even without a Magic-Mart, it's kind of wacky that you can use Craft Wonderous Item to make your own manual and use it to build a golem for less than it costs to make a golem with Craft Construct.

There is, however, one good reason not to do this. Golem manuals are spell trigger items, so unlike the golems themselves you can't waive prerequisites with an increased Spellcraft check during their creation. As a result, you need actual access to the spells involved, limiting this option to level 13+ for clay and flesh golems (requiring Resurrection and Limited Wish respectively) or level 15+ for iron, stone, and stone guardians (which all require Polymorph Any Object). It's very possible to create the relevant before then, but you'll be paying full price.