I’ve recently swapped over from Eurosport Player to Discovery +. It’s slightly more money per month, but you do get access to the other Discovery channels. I was paying £4.49 a month for Eurosport and I now pay £6.99 a month for D+. You can pay yearly for £59.99, which works out at £5 per month.
I did toy with the idea of GCN+, but I mainly watch it on Apple TV and I’ve heard that the app can freeze and crash. I’ve not had any problems with D+ and swapped over about a month ago. The cycling racecoverage on D+ is exactly the same as you get on GCN+ and Eurosport.