A member has a profile. The member can upload a series of pics and movies - then set a pricetag on them. The user can see how many sets of pics and movies the profile has and can chose to download by selection. The download costs xxx amount of $ which will show on the members account. When the fee is paid the user has to be able to download instantly.
Escrow: none, you do the job and get paid!
You will do a demo on your own server and I will test it there.