I've picked up various tamagotchis in jumble sales held at local schools. There are about 4 sales held per year in my area.
I usually pay between 25 pence > 50 pence for them.
I've found V1s, V2s, V5s...
I'm sure that before long I will find a V5.5 and a Music Star!
It's always interesting to start them up and download to see what the previous owner named their tama character and what kind of character they managed to get
If getting my V2 for Christmas counts, then I got it for free. Other than that I have a Music Star that I bought from Target for around $15. Those are my only 2 tamas.
The cheapest tama cost me 50 cents at Goodwill. It was a half-off sale on a Saturday. They had 4 of them @ 99 cents each, minus a half. I bought all 4- a V1, 2 V2s, and a P1. All for only $2.00!