I hadn't dabbled in golem manuals since 2nd edition, so the question intrigued me. Upon perusal it looks like the manuals are poorly suited to the more regimented item creation rules, so benchmarking from the existing books is probably the way to go.
The clear commonality among the example books is that they all seem to require exactly the same spell list and caster level to construct that the golem itself does, which makes a lot of sense. The price is less exact, but seems to hover between CL x 1,000~1,5000 and the caster level bonus might roughly be Cost/6000 or so, rounded however suits your campaign. The exact details need not be examined too closely since the book is of absolutely no use unless someone actually makes the golem, at which point the book can be considered an expendable and the real impact to wealth by level will be the golem itself.
Applying those guidelines, here would be a Golem Manual : Glass...
CL 10, Animate Object, Flame Strike, Geast/Quest, Spell Turning, provides +5 to Craft (Sculpture) and +2 to Caster Level for purposes of constructing a Glass Golem. Cost: 12,000 GP
Much like the Golem Manual: Flesh, the book would be a significant expense relative to the value of the golem. It's greatest value comes in access to spells that might be hard to manage at low level.
Golem Manual : Adamantine
CL 20, Crushing Hand, Geas/Quest, Heal, Stoneskin, Wish, +5 to Craft (Sculpture), +4~5 to Caster Level for purposes of constructing an Adamantine Golem. Cost: 30,000 GP
Much like the Golem Manual: Iron, the book is a pittance compared to the golem itself, most useful because of the caster level bump as anyone with the money to make one probably has access to the spells as well.
