I replied to your post, although if your bank takes 10% off the top to begin with, the issue isn't with bitcoins, it's your bank's deposit fee.
So if you buy $5 worth of bitcoins, it costs you 61.2% in fees.
If you buy $50 worth of bitcoins, it costs you 9% in fees.
If you buy $100 worth of bitcoins, it costs you 6% in fees.