Any question answered...

If I convince a friend of mine to sell me a bike from his independent bike shop at trade price. Would I be able to resell the said bike in a few months and recoup what I paid?

I need a bike at the moment, just something practical and hyrbidy. Either SS or hub gears. But will prolly want to be rid of it by summer again. Im not sure what shop markups are like.

But he can get in genesis, dawes, marin, gt, merida, etc.

buy a decent MTB or a flashy SS and you will very close to recover the in late spring.
it is when everybody who dont have a bike try to get one for the summer rides.

be ready to lose a bit too.
if bike cost new to public £350, you mate get it for £280, you could reselt it easily for £250* **
*all this numbers are fake
** I dont really know what is the marging from public price to trade price