What to buy to extend wifi with surfsoho, recomendation needed

I extended my wifi range to 20/40 from 20/20. I am able to get a good connection outside now and near the router but now always in other parts of the house. I have a tplink to extend to the other part of the house but that is not working as well as it did with my old cox gateway. I saw an add for a netgear orbi mesh wifi. It is expensive and I wonder if it is necessary or would be useful. Or do I need to do some soho settings differently.

I dont understand the question. What does 20/40 mean? How did you extend your wifi range? With any extender there are many things to tweak such as the channel used on both sides (client side and router side) , the WiFi frequency on both sides and physical placement. Play with it a bit before giving up.

Netgear Orbi is said to offer great Wifi performance. But, expensive and I am not a fan of Netgear in general.