This is not a deal for everyone, only those who are contact lens wearers however Costco have always been cheap for solutions.
At the minute there is 20% off Bausch & Lomb products
A 3 month pack of Easysept is usually cheap at £10.33 (£3.44 per month) however there is currently 20% off making it only £8.26 for 3 months equivalent of £2.75 per month.
This is currently selling at Tesco for £5.48.
Hope this is useful for someone