[Is this normal/appropriate?]

Students presenting for professors is definitely normal and totally appropriate, at least by the norms of this field.  It just seems strange to be given an order requiring a large personal expenditure (which I can pay without hardship, but still...).

[Is this normal/appropriate?]

My advisor accepted an invitation to give a talk at a conference and subsequently instructed me to prepare a submission and deliver the talk instead, since he would be unable to go.  I am happy to do this, but the registration for the conference costs over three hundred dollars.  As soon as I brought up the issue and tried to get him to approve the reimbursement  paperwork, he simply stopped replying to my emails.  He isn't on campus so I can't ask him in person.  I am pretty sure he wants me to pay the expenses myself.  Is this normal/appropriate?  Am I being unreasonable?  I will probably just end up paying, but I wanted to do a sanity check and see what other people think.