I've never had a tenant ask to see my invoices.

The best thing would be to find the buyer here or through your database and sign an agreement that you will be assigning the contract to them at closing. at the time of signing this agreement you can invoice your buyer for the finders fee.Now, please note this is by far the best and easier way to assign contract and how we used to do it in NZ back in the day almost 10 years ago. at some stage the RE agents Authority in NZ deemed these type of transaction as been work of kind of like Agent with no license.... and someone got fined. then most wholesalers stop doing it, at list out in the open.. 

I do not mark up maintenance/work invoices.

(It's a nice 2 story 3/2 with 3/4 acres in a beautiful area.)I've been looking at purchasing but anything in the neighborhoods that would work for me is way out of my price range and anything that would be a good deal is snatched up too fast by them danged house flippers (who I wish I was one of.)

Dang!

Is it true work that you or anyone else invoices for in general? 

I sent her an invoice for everything owed, and forgot about it.

If there are charges back to the tenant, I would get the repairs made quickly and invoice them once complete - typically we make the terms "payable upon receipt". 

:)  I sent in plumbing invoices to request an adjustment of the ridiculously high water bills for several properties, per the procedure told to me by customer service, and it seems those emails have gone into cyberspace.

She must remove the camera, or you will invoice her for the removal if the camera is not allowed in the lease.