Becoming a bean grindy wanker is great and you should do it. Cheap electric burr grinders aren’t bad at all, probs in the £50 range.
I’ve used a Hario hand grinder, about £30 and it was decent but sloooooow and hard work.
If you go through your beans fast, then getting the shop to grind them is fine, but fresh ground beans do make a big difference.