Cindr isn't designed to be a fully fledged e-commerce tool. However, you can use Cindr to sell items via PayPal using the 'Sell with PayPal' Blocs found under "Add Blocs to Page" > "Apps" through the Side Menu.
Once you've added a PayPal Bloc you'll need to enter your PayPal registered email address. This can be done by clicking the Bloc, to show the editing bar, and going to "PayPal Settings" and entering your email.
From within the Bloc you can add an image, set a price, and include an item name and description the same as you would edit the text of any Bloc.
At present there are no options to include additional costs such as postage, so you'll need to include everything in the product price. Prices are set to USD.