I've just acquired an AMOD AGL3080 data logger for $60,
and I am fairly happy with it. I'm correcting the map
around South Park and North Park in San Diego,
plus surroundings as I happen on them.
Walkabouts and eyeballing for gross corrections,
GPS for fine measurements.

The Tiger mapping data that initialized OSM
in this area has many streets listed that were
only contemplated or are extrapolations along
straight lines of streets that are actually intermittent.
The interruptions by canyons here necessitate many adjustments.