Should Oil of Sharpness not be available to to low-level characters?

I am currently preparing an adventure in a wizard’s mansion and need to fill the building with interesting content. Having a laboratory where the party can take some stuff seems like a good idea.

Oil of Sharpness looks interesting as stuff to take but is a very rare item. The general assumption seems to be (such as discussed here) that very rare items are given out on high levels. My party however is tier 2 (about level 7). Also, contrary to weapons which appear in different qualities (+1/uncommon; +2/rare; +3/very rare) Oil of Sharpness exists only as +3.

Given that Oil of Sharpness is a consumable item I suppose the risk of ruining things is neglible compared to the risk associated with permanent items. I could also imagine having a lesser variant (with a bonus of +1 or +2). Would I risk balance issues by giving my party reduced-bonus Oil of Sharpness or even the full-bonus one?