I am planning to attempt to walk across the whole country of Luxembourg in a perfectly straight line, à la GeoWizard's straight line missions across Wales and Norway.

I have a lot of hiking and backpacking experience in the US West and recently moved to Europe within 2 miles of the Luxembourg border so I figured I should make the attempt to give GeoWizard some competition ;)

I have everything I need except for my GPS system figured out. Tom (GeoWizard) uses a Garmin GPSMAP 64s, which has a dedicated screen which displays the line being followed as well as the critical ability to have custom maps displayed. I am trying to find a way to avoid having to buy a GPS this expensive. I currently own a Spot Gen3, but think I might need something else. Anyone know of a way I can follow a straight line and record my location pings without having to buy a $300 GPS system??

Also GPS general