Cheapest secure courier/shipping to Europe please

[JarethTheGoblinKing]

I'm selling some shoes that are likely to go £30-50, and I'm getting a lot of overseas bidders. Is there a courier service that I can send them and get a signature that costs less than £20? It's approx 800g, and I've got bidders in France and Poland.

I'm selling the shoes on behalf of my sister, so if they went missing I would potentially have to refund my sister as well as the buyer, which is why i want to be so careful.

Wont international signed for cover them? I've sent coats before international signed for.

I haven't sent anything outside the UK before so am unsure of how it all works tbh. I looked at the Royal Mail website and it says it's only tracked until it leave the UK (it can also take up to 28 days). I'm unsure about the ebay policy on refunding people if things are sent within Europe.

High bidder is in France, she hasn't contacted me about shipping, she hasn't asked about costs..It's just annoying