I brought mine brand new on ebay for $30 and I love it, I got it at 13 weeks and can find baby straight away everytime.
I bought one online and started hearing it at about 16weeks at home. I think its worth it. If I feel like hes not moving according to his usual patterns I will listen just to make sure his heart rate is good. Its more for my piece of mind than anything cause I worry a lot but its been fun!
I also bought the sonoline b doppler got it around 12 weeks and was able to use it right away. sometimes it was hard to find the heartbeat in the beginning but was always eventually able too. only cost me sixty bucks and used it everyday of my pregnancy! It was great because i was a big worry wort because of previous miscarriage.
I bought a Sonoline B doppler from Amazon and heard baby at 12 weeks. It came with the gel and the manual and only took 2 days to get it in.
The rentable machines are great second time renting it. It's a go. Very fast ship, comes with gel, batteries, clean machine and works great.
Fyi Do not buy from store they are a waste of money.
Mine was heard at the doc at 10 +3 or so. I'm high risk so I decided to rent one for peace of mind..me and hubby have listened in the morning and at bedtime..love it. I rent it for $30 mo but have a coupon if your interested to save $10 bucks! I'm 13+6 today and have felt baby move for about a week now.
They used it on me this week and found it fairly easy. I was 14weeks to the day. It is pretty cool. But I've also heard some of the rentable machines aren't the same quality as the clinical ones. So its really up to you to try it out :-)
My dr used it at 11+5 and heard nubs heart beat. Was just a little hard to find....
they listened to my baby for the first time @ 16 weeks