Awesome news Lovedup!!!
No I didn't end up buying one - I just got busy with work etc and forgot about it. I read in one of Lissy's posts that it caused her more stress as they couldn't find the heartbeat a lot of the time. Now my FS is back from leave I will be seeing him more regularly anyway, and after the NT scan on Tuesday I feel much less anxious.
The website TK gave me (sweet beats or something???) lets you hire them on a monthly basis. Might be a better option than buying?