changes to my site

i want my customer to have the option to finish registration when they come back and sign in i want a button that will allow for them to finish registration. currently new customer who dont finish the payment process and come back get message to Waite for admin. i need customers when they come back to have the option to finish registration. also i want them to get friendly reminder to finish registration. on the page that shows price once you sign up i need the price to change from 59 to $19.95 but i want you to make it look like good deal $99.99 crossed out and show $19.95