SOLVED
I have just found the issue. Basically, my cache was not allowing me to see that my product.tpl page was actually displaying the £1.00 but the cached version was still showing me the £0.83.
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I have just found the issue. Basically, my cache was not allowing me to see that my product.tpl page was actually displaying the £1.00 but the cached version was still showing me the £0.83.