Yes, I would like to say that my cost basis is lower than it actually was (and thus pay more taxes).
Quick story, which I think is mostly correct (but I can't remember all details):
I own shares of the GLD ETF. I believe that a very small amount (I think about .001 per share) is sold each year by the issuer to cover expenses. Thus I need to pay taxes on my gains on those shares. If I owned 100 shares (worth about $13,000), then the amount sold would be about .1 shares, or about $13 worth.
I don't even remember the entire process, but it was confusing and time-consuming to figure out the exact cost basis (it was not just the acquisition cost - I had to find random tables, and enter a lot of data into Turbotax, I think because they sell them every month).
Long story short, I spent at least a couple hours researching and entering this data. I ended up paying capital gains on something like $3, where if I just entered $0 as my cost basis, I'd pay capital gains on something like $12.
So is there any problem (legal or otherwise) with entering $0 as my cost basis, and thus paying more tax (while saving myself a lot of time)?