We bought a porch awning at NEC, we liked two and bought at the stall who gave us the best discounted price, don't be afraid to negotiate as it worked for us. Another trick is to go on last day they are normally keen to not have to cart the heavy stuff back to the shop/warehouse and more flexible on price.
Amazing family weekend with old steam engines, classic car displays, market stalls, and full catering and bar. And camping on site - Save £25 by booking in advance.