I've ordered from Nature's Grub several times now (it's never even occurred to me to look at postage as I've never come close to the minimum spend, mine is always way above! The buns love it, there is the occasional bit of "rubbish" in which is inevitable in most stuff that is grown and harvested, but given that it is all handled closely just in doling it out it isn't a problem. Their delivery has always been incredibly quick and easy to track.
A lot of this type of stuff comes from Germany, they seem to grow and use a lot more than we do here - I used to use Grunhopper when we first got the buns til I realised that I could buy the ingredients in bulk myself instead, and I was paying a lot for the dried veg bit that is heavier, but they get fresh anyway.
I've had most of the stuff they sell that is suitable by now, so if anyone wants to know what something is like I'm happy to give feedback. They do two types of dandelion, I got the cheap one last time which is quite clumpy (Freja quite likes chunky dandelions it seems!) but we feed that fresh when possible anyway so I'm not too bothered.
If you can afford the outlay, buying raspberry, nettle and dandelion seperately instead of as the leafy mix is about £3 a kilo cheaper
The dandelion roots are lovely!
Also watch out to get the whole leaf of some of them rather than the chopped stuff.