Caster Level+ Weapon Property?

[English Language]

I need to know, is there any weapon properties, magic or otherwise, I can put on my weapon that would increase my Caster Level for a class? (Bard in this case).

If not, is there a workaround I can do for it? I'm getting a custom homebrewed weapon soon and boosting my Bard CL is part of it's property.

[Lifat]

No such thing exists by raw.
It is also a very strong thing and should be very expensive.
Just look at the Ioun Stone for price on an item that boosts CL with 1. Granted it is semi-slotless, so more expensive than it would be on a weapon, but I would likely price it at around 20k, because the ioun stone prices it at 30k. (This assumes that I would allow it at all, and I might not.)

[Archaeik]

The concern with doing something like this is potentially opening the door for a slew of +1 items for every slot imaginable...

Typically, what you find available in terms of CL increases are bonuses that affect a single school or spell descriptor. I'd be reticent to allow a CL bonus on a generic(ie non-artifact) weapon though... it's just not the typical slot for that. (although I suppose there's an argument to be made here about rods) Also, it would be pretty strange to see it as an enhancement bonus equivalent, even if it was pricey.

Anyway, pricing: it's pretty clear from the Ioun stone that a slotted +1 CL item would cost 15k, although I have no idea how to arrive there since the only requirement listed is CL12.
Other items I'm seeing Karma prayer bead (+4 CL for 10min 1/d) - 20k, and some robes that offer +1 CL [element] for 11k(they have some resistance so more like 10k)

Depending on the wording of your bonus, I'd work off the orange prism and use the standard formula of bonus^2 * X where X = 15k
If only a bard can benefit, I *suppose* you could knock a percentage off (as it appears to me the prayer beads did this), but in general, I wouldn't recommend this since in all practicality, that's just cheese.
Estimate for bonus equivalent: if you are compelled to go this route, it's at least a +2 equivalent for a single +1CL; a +3 keeps it less accessible, but easily makes it not worthwhile as the enchants pile on; the exponential growth is a really bad model for this.

Potentially consider having the item require some kind of sacrifice of daily resources to turn on its power.