HI
I was in the same boat as all of you, looking for some chepo GPSr for my troop. Tried for months and I started to look at Ebay. There are a lot of them. I got 2 used Yellow Etrex (in very good condition) and the computer cable with the serial to usb converter. I ended paying $20 for one unit and $25 for the other (shipping was included in every one). For less than $50 I got two units.
Some time you can see someone selling a lot of 5-10 units. I saw a lot that was a good deal for $150 but I didnt take it because of the shipping charges, the seller only use UPS and I live in Puerto Rico, I did the math and it was around $100 because he will send it nextday+tax..... at that time I didnt have the money available and it was a few minutes to the auction to end and I like to give a detailed review to each offer.
Remember, The tricky parts is to spend some time looking at the auctions and dont hesitate and buy the first cheap offer, dig around, try to get the most out of your money.
Ramon