.. Currently on 20meg sky unlimited, getting the full 20meg download, paying all together something like £13 for line rental £5 for calls and £7.50 for broadband....
Would BT be the best for unlimited usage? Works out at over £40 a month tho doesn't it? Compared to £25.50 for Sky
If you worked the cost out over the length of the Infinity 18 month contract, it is quite a bit less than £40.
Infinity is £28 per month, but you currently get 3 months free = £420
If you pay the line rental for the full 12 months upfront, it works out at £10 per month (normally £13.90). So for arguments sake, say you paid £120 upfront now, then renewed this again 12 months on. So line rental would be £180 for 18 months.
Total of £600. Divide that by 18 to get the monthly cost = £33.33.
And for me (subtract the above total figure with the £50 Topcashback) = £30.55 for the broadband and line rental. That's not much more than what you are paying now.
Not sure what your current Sky package includes, but the above BT deal comes with calls to UK landlines anytime of the day.
So in terms of cost, you won't be paying a lot more. But it all depends on how stable/trouble free Infinity would be (for you) compared to what you have with Sky now. I have not heard good things about BT customer services though, so bear that in mind should you need their assistance.