I need help to upgrade my social networking site

We have an exciting & growing social networking site and I would like your help in bringing our website to the next level with more sophisticated features. Must be proficient in PHP, MySQL, Ajax, & jQuery. Must have worked on social networking site previously & can show which sites these were. It is relatively simple if you have the coding already, it is just that there is quite a bit to do. We have a budget of $250 and need to achieve all that can be done for $250 in the order as follows asap. Let me know what you can do for $250 - please note - winning bid will not necessarily be able to do everything on list. I will also be working on this list at the same time. Features include: (1) an automatic 'show more' system on our messages with approximately 20 feeds shown, then 20 more shown, then 20 more shown etc - it must be automatic (e.g., something like [login to view URL]); (2) add a shopping cart to our system (we currently have no shopping cart): (a) must be of the highest quality, easy to use, fresh looking, allows customers to add items, remembers items, most popular item listing, loading messages if needed etc; (b) enable ecommerce to be processed on that site (I haven't decided which system yet although it is likely to be paypal or google); (c) the shopping cart must be able to be used if a member is logged in or not logged in; (3) we are currently able to open a print preview of a message with pdf preview (so they can print their message)... however this only allows 1 database cell to show, we need to be able to add other cells to this pdf; (4) our messageboard system needs an upgrade: (a) so that members can add any number of images to their message - in jpg, gif etc but limited to 700kb per image - images would be stored into the members directory with a specific image name that we provide, the image name is then stored in the database, and members can give each picture a title or description - please note, an animated 'loading' image and checks for the size limit are required - please note the database for this has already been developed - we just need to be able to add the images in, to link them to the corresponding message, and to output the image onto the message and into the feeds; (b) enable autosave as soon as the person starts to write... and also to enable autosave when editing messages; (c) if a member adds a website url, our website recognises this url as a website and gives it an active link (& possibly a thumbnail image from the site, the title, & description of the site). In addition, when link is clicked it opens in a separate tab; (d) if a member adds a YouTube url the website recognises it is a YouTube video; (e) add an autocomplete system so that if member 1 is writing to member 2, their name will come up and their details will be uploaded into the database for that message; (f) members need to be able to write a message for more than 1 person (such that more than 1 person can be linked to 1 single message) - the database for this exists but we still need to enable members to link their messages, and the output must show who is linked; (g) members need to be able to link with other members to write a message (e.g., where there is one broad message and others can be added so they can add individual messages of their own) - the database for this exists but it is not active; (5) add privacy feature where their friends only can see their message (at the moment messages are either public, private, or members only); (6) members need to be able to share messages on their friends Facebook walls (not their own wall); (7) at the moment members can invite friends via Facebook, however, we need to also allow them to find their Facebook friends (like Instagram does); All features must be extremely secure. In addition, I would like some advice in making my site more efficient (e.g., if you see something that could be better, share and let me know)