Looking for an Social Media / Traffic and Lead Generation Guru to help me with driving traffic and sales to my site.

Please note - this job is only suited to someone who has a proven track record of being able to drive quality traffic to eCommerce sites that converts to sales, and expands the reach of my site and brand to new customers. You'll need to be confident in your knowledge and skills, as this won't really work if you can't produce the goods. Basically I have a huge amount of physical stock I have picked up from liquidators (in the fashion/accessories industry) that I am wanting to sell for low cost (focusing on high volume turnover rather than high item profit margin), and I'm looking for a sales/marketing/traffic lead/social-media-guru type someone to help me achieve that. I have finished my website, and am now working on ways to send traffic there in an economically sensible way (as in it makes little sense to pay £1 per lead when I may only make a few pounds on the item the person may purchase), and I'm looking to avoid past mistakes on other projects where I've paid loads for advertising on various platforms with few results to show. I am unsure of what the best approach is to get to my goals (I've looked at google ads / facebook / instagram etc), so am looking to have someone help guide me down whichever path may be most profitable for my business, so ideally I need someone who is great at marketing/sales/lead generation etc and can help me navigate the journey. I would perfer a longer term arrangement, though wouldn't like to trap someone into something they don't want to be doing so could do a rolling month by month extension type scenario. Due to having been burnt in the past by large upfront payments for work that doesn't eventuate or produce results I'd be looking to make a payment agreement that is win/win - for example a small weekly/monthly retainer (or similar) with some form of profit share on the results of the work.... so the bigger money would come if you're the type of person who can actually drive traffic and provide measurable results. For example if we arranged something like a 10% commission on every sale and sold through one particular lot I currently have available to clear we could be looking in the range of £1000. I have several of these lots to sell through and more available if I take up an option to purchase them. Please note I'm not trying to cheapskate work here which is why I am prepared to offer a retainer - as a serial business builder I just find that when people have a vested interest in something they tend to be more passionate about the project and that's the sort of person I need working alongside me in this. My initial strategy has included looking at building social media, and while I've been getting a lot of attention to ads for individual items posted in places like Facebook MarketPlace I'm struggling to move beyond time consuming individual sales through those platforms to traffic (and multi-item purchases) on the actual site. I am reasonably negotiable on any terms of a working agreement - - please note I've listed this job as a 'medium sized project - £1500-3000' as that seems reasonable but obviously is subject to an agreement and the results produced. I'm very open minded on ideas to get the project to where it needs to be. Please ask any questions if you need more info to find out if this job might be for you :)