It's actually probably worse than the conj ability in general use, except that it needs ingredients. Which can kind of be anything, especially when used on something to change it into something else similar, but not as annoying. Can you expend "scenery" to the value of? Even if you have to throw a few gold pieces at the ritual in the process? The broken thing has to be worth less than the properly made version, and it's "crafting", so it can alter things, not just conjure them into being.
Ie, a door with a hole in it. A bit of floor into a trapdoor/chute in the floor to the level below. A window in a wall. A thin wood (and metal) bridge over a chasm. Etc.
No size restrictions, and crafting can alter things already there. As long as it's a "finished item" by the time you're done. How much is a broken lock worth? Less than the 100'ish gold piece magical lock you made it from? That you expended in the ritual? That was locking the chest you wanted to open 10 mins ago? That you totally own and is *your* item to be expended at will..... You own that devilishly clever and high DC lock, you just chose to god-craft it into a crappy/broken/already-open 100'ish gold worth lock. With a hammer. For reasons.... But you could have made it into anything. You didn't even need to "own" the lock to expend it. Anything made of metal is fair game, and virtually anything you make from it can be really badly made if you need it to be. Or very well made. Depends.
If it has to be worth the same amount, then you're still the able to do it to everything up to 100 gold worth, which is a lot of breakable stuff. Gold->platinum goblinium if you still need it to be crappy. If you can expend more valuable items to make ones of lesser value, you're fine. Absolutely golden.
It might need tools and ten minutes, but it's still a very small amount of reality warping available at very low levels. Conj can't use things as the ingredients, which is both good and bad. It's nowhere near as good as Illusion 14. But changing stuff into other stuff fairly quickly is still pretty good. It's more-so for that, not for actually making useful items or tools. There's no size restriction, and dodgy stonework/woodwork with a few metal bits on it is cheap. But is it an "item"? Is it "simple"? Altered doors probably are, especially if carts are considered simple, and most doors can't be worth more than 100gp. Is a trap-door and a chute an "item", or a window, or a bridge though? This is the skill's only downfall. What the heck is an "item", considering rowboats are on the equipment/transport list? Are they not "items"? Are they "simple" "items"? Can't people buy stone statues costing 99 gold (with menacing spikes of iron on them, of course), as "items"? Surely other sorts of masonry/woodwork/metalwork count as "items" too, even as discreet parts of something else. Crafting can alter stuff, making "items" in stuff there already.
Is a bow "simple", and is a crossbow? As long as they're not magical, they're on the "simple" ranged weapons list. A window is just a lack of wall in a possibly metal box or frame. That's pretty simple, and it doesn't even have moving parts.....
It's fairly openly worded, and many useful things and "items" were probably "crafted" in some way at some point in time. They took time and labour to do, transport and materials, not a lot of gold in of itself, which is exactly what this skill covers if the stuff to be used is already in situ. Big, cheap, reality warping stuff, menacing with spikes of iron, all done in ten minutes.
So keep your hammer, your chisel, your pick and your axe ready. Stoke a fire and prepare the mini-anvil. Shit's about to get Orky.
(for semantics, windows are considered a finishing item in construction terms. When they are done (and the doors and the locks are put in), the structure is considered a "finished item". Everything else is just "window dressing", thus the term. Strangely enough, half of these things that get put in afterwards are referred to as "finishings", such as paint, rendering, coatings, and even sometimes carpet. But from a structural standpoint, it is a "finished item" when the doors, windows and locks are in, because they tend to go in last.)
(the skill doesn't actually say you need tools, but it does give you the ability to craft stuff, and crafting stuff needs tools. It's a lot more powerful if the ritual lets you craft anything from stuff without them. I chose the weaker reading, and it's still quite good. Sort of a transmute, not a conjure, as long as you're willing to throw some gold at it. How many things actually are worth more than 100 gold? Not doors or windows, certainly)
(note: this is a vaguely useful use for a bladelock's "weapon on demand" feature too. At least you've got one of the tools you might need to finagle this, on-call, at any time. Warhammers and battleaxes might not be made for smithing or woodchopping, but they're still hammers and axes. They could do the job in a pinch)