Garmin 305 is great gps unit that is nowadays selling at much lower prices than similar units like Garmin 310 and Garmin 405. If you are in market for such device check out this site:
http://garmin-305-review.com
http://garmin-305-review.com/garmin-305-vs-310/
I hope you can find some useful info about differences between Garmin 305 and 310 and decide what is best for you. Read before you buy and get the right thing for you.
You can but this devices here at good prices:
http://www.amazon.com/gp/product/B000CSWCQA/ref=as_li_tf_tl?ie=UTF8&tag=mirjamitropho-20&linkCode=as2&camp=217145&creative=399377&creativeASIN=B000CSWCQA
http://www.amazon.com/gp/product/B0025VKW5K/ref=as_li_tf_tl?ie=UTF8&tag=mirjamitropho-20&linkCode=as2&camp=217145&creative=399377&creativeASIN=B0025VKW5K
