Where are sellers sourcing discounted 'Three' SIM cards - Are they legit?

On a tangent, get Leebaarahha

For saving £5, do you want to find out the hard way if they are legit?

If it's a legit company or phone reseller they could've been given them for free or pennies each as part of a promotion or commission deal with a trade supplier or the network directly.

I have noticed these, I assume they are phone shops etc who get commission on a SIM sale and top up.

I believe they are just topping up with £10 then buying the £10 bundle.

I've never bought a Three one but I did buy an several O2 Sims a few years ago, £6 each with £10 credit and all was fine.

It's generally quite easy to get your money back on eBay so honestly I think you're ok, and if it's not you should be able to do a claim.