Cheap Garmin Computer

Hi everybody,

I am about to do my first Ironman in 5 weeks and just switched my Aero HC drinking system to Aero HSF BTA. That means I am no longer able to mount my Geoid CC600 on the drinking system.

Therefore m,y question: What is the cheapest suitable Garmin computer to show my pwoermeter watt, HF, Time, Cadence, Km on one page. I do not need navigation or the newest shit, just a computer who is not lacking and so. I am totally open to by used so it does not need to be the newest.

Thank you :)