Not necessarily. The misc is usually a refunded amount or a Pad to cover any incidental costs. If it is not used, it will come back to you. $500 seems like too much for a $75,000 sale, but the specifics of your purchase may have warranted it. Document storage or transaction fees are often times charged by Realtors since they do have to pay for transaction coordinators, etc. I have never heard of a document prep from a Realtor, lenders sometimes charge it, or it could be a title company charge. Ask who it is being paid to. Recording fees usually are $65-$90 but the title company can explain why it may be more. The HUD 1 settlement statement will be a more acurate accounting than a estimated cost sheet that Realtors prepare. You have the right to have all fees explained to you by the agent, their broker, and the title company. Ask questions. All fees are negotiable and each contract is unique as to who pays what. If you have agreed to it contracturally, it is yours to pay. If the fees are being paid to the broker and are those outside the purchase agreement, or buyer's broker agreement, you have the right to have them explained.
Best of Luck.