I want to get the Attachment URL with via REST or Javascript. Is there an easy way?

The reason I need this, is because I want to build a marketplace in my company.
1. User creates new list item
2. User can upload a picture
3. User saves form

I want to display the list item in a "nice" way with picture, name, title...
I got everything, but **not** the attachment URL.

Here my code:

```
<script type="text/javascript">

$(document).ready(function() {

    // Rest URL
    var requestUri = "/_api/lists/getbytitle('Marketplace')/items";
    var picUrl;

        $.ajax({
            url: requestUri,
            type: "GET",
            headers: { "ACCEPT": "application/json;odata=verbose" },
            success: function (data) {

                $.each(data.d.results, function (i, item){
                   var title = item.Title;
                   var searchOffer = item.SearchOffer;
                   var category = item.Category;
                   var description = item.Description;
                   var price = item.Price;
                   var id = item.ID;
                   var authorId = item.AuthorId;

                    document.getElementById("market" + i).innerHTML = "<img class='img-responsive' src='**???**' alt=''><h2>" + title + "</h2><p>" + description + "</p>";

                })
            },
            error: function () {
                alert("Error getting the Marketplace Items");
            }                     
        });
  });      

</script>

```

In the innerHTML I need the Attachment URL as source.
An other option I already tried was to use this requestUri:

```
items?$select=Attachments,AttachmentFiles,Title&$expand=AttachmentFiles

```

But then I cant get the ServerRelativeUrl into a variable... Any ideas there?

I tried it also with a second REST Request **/items(id)/AttachmentFiles**, but it can't be that hard to get this, right?

Any help?