Advice on sigma lens

[local lens]

Hi so im looking to get a reasonably priced telephoto lens i think i have decided on the sigma 150-500 f5-6.3 has anyone had any experience with this lens? also i have found a refurbished lens for about 130 less than the cheapest new one I have found, is getting a refurbished lens a good idea or is it worth getting a new one? this is the one I was looking at

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any advice would be good thanks