the cheapest garmin edge is about £100,very accurate but sure there are cheaper alternatives
Bryton 20 is good less than £100, also options for HR and sp/cad, but no breadcrumb, the 40 I think I saw about the £130.
Endomondo is a better than strava for logging rides, as you can export both tcx and gpx files, and timings see better, strava I think uses different times for actual ride time to that recorded by my garmin.
Todays ride Garmin Time 1:53:51 moving time 1:53:33 elapsed time 2:26:35
Strava Moving time 1:54:21 elapsed time 2:26:32 so you can see that the avg speed will be lower 16.6mph compared with 16.7mph on garmin
Endomondo figures are 1:53:51,
Also Strav's elevation data leaves a lot to be desired.