Can I leave "sale amount" on memorandum of P&S blank?

[Jose Falconett]

Hey guys so legal question, feel free to answer if you might have an idea but if you're an attorney that'd be all the better! I am a wholesaler.

So if you didn't know recording a memorandum of purchase of sale agreement is a way to secure the real estate deal, "clouding the title" so that the seller can't sell to someone else after selling to you. 

Now upon reading these sample agreement's it ask's you to fill in the "Sale amount" and to attach exhibit A...(the purchase contract itself). 

The problem is that I don't want to share the sale amount in the memo that goes into public records because I wan't to prevent my profit from being disclosed to the end buyer to prevent them from having to much bargaining power of course. 

So would I be able to leave the memo sale amount blank or white out the sale amount on the "exhibit A purchase agreement"? Would this invalidate the document at all? Any recommendations would be great!