Get your shopping carts ready. A new Costco is in the planning stages for Nashua that would replace the current store according to unionleader.com. The new store is proposed to be a whopping 156,964 square feet with around 800 parking spots. The proposed Costco would have a gas station attached along with a storage facility. I'm actually a member, I would recommend getting gas there because it's cheaper. I'm not sure if you know this or not but did you know that Costco sells cars? I once bought a car thru them. I also got car insurance from them which was at that time cheaper.