Codeignitor website speed optimisation.

Hi there, i currently have an e-commerce site built on a custom cart and the codeignitor framework, on decent hosting the site is taking 6 - 8 seconds to load, i can see that caching has not been enabled and there has been very little optimisation for load times.

Can you please quote me a price to optimize the site to load as fast as possible, preferably 2-3 seconds or less.

Website is: https://www.cbk-haylingisland.com/

This job is open to a few people, please can you quote me the price you offer and secondly how long it will take to be completed.