So I've never had someone play order of the scribe, one of my players asked if the Wizardly Quill meant they don't have to pay transcribe/copy spells into their spell books. Since the cost is for 'ink and materials'.....that seems extremely broken since that would basically mean he wouldn't have to pay ANYTHING for equipment, especially since the quill doesn't have a listed duration. 

There is Xanathars for gold cost for scrolls.  There is the master scivner feature that allows a caster to make a single level 1 or level 2 scroll that only they can use and it disappears on long rest.  I would not allow them to create free spell scrolls outside of the class feature, it will be game breaking in short order.

The Wizardly Quill ability is clear, it lets you scribe spells into your spellbook.  It talks about scribing scrolls at level 10, so it cannot do that until then.  It specifically mentions time, but not money.  As such, I would say it does not save you any money at all.  Effectively it reduces the time down to almost nothing (2 hours per level becomes 2 minutes per level).   Effectively this means you can scribe a scroll into your spellbook during a short rest.  

Compare that with the typical wizard sub class, it lets people cut both the time and money for one school of magic in half.  That is not enough to do scribe the spells into your book during during a short rest, unless it is a Cantrip.   And you need to sleep during a long rest.  Effectively Quill is the ONLY ability that lets you scribe spells during an adventure - all others have to do it during downtime.

In my opinion, even if the Quill does not affect money at all, it is a better ability. 

QED, the Quill does not affect money costs at all.  It mentions nothing about it, and it is already over-powered.

Quote from locustgate >>

 So I've never had someone play order of the scribe, one of my players asked if the Wizardly Quill meant they don't have to pay transcribe/copy spells into their spell books. Since the cost is for 'ink and materials'.....that seems extremely broken since that would basically mean he wouldn't have to pay ANYTHING for equipment, especially since the quill doesn't have a listed duration. 

 Scribing scrolls isn't just "ink and materials", it also includes the experimentation process involved in sort of reverse-engineering the spell from another wizard's book, in another wizard's own unique notation, and converting the formula into yours. It takes more than just ink and the standard material components, which is where the gold cost comes in. Admittedly, the book doesn't do a great job of explaining this, it thinks you should just be satisfied with the explanation of "the gold cost is important for balance reasons." Which it is, it's just not a very satisfying answer. 

There are general rules regarding the cost of scribing spells that apply to all wizards. Those rules hold unless something explicitly replaces them. The quill replaces the time it takes, but not the cost.

"Ink and materials" is just flavor text describing what the gold cost represents. Having an infinite supply of ink does not change the cost of these actions, because there is no specific wording that says it would.