That really is quite an area to find seed for without taking out a mortgage, Ricky. I have been looking at costs of doing something similar, and it's ridiculous! I think your best option is to wait a while, if you can, and in a few months' time, go out into the country highways and byways and try to harvest some of your own. Of course, if you want specific flowers, it may be worth buying small amounts of each and sowing a small corner, with the idea that in due course these will naturally seed themselves and cover your 500 square metres, but you could be in for a bit of a wait.

I would contact www.grasslands-trust.org for offers, and also meadowmania.co.uk. 500sqm is a large area, so you will have to be prepared to pay that bit more to seed it all. As Gattina suggests, collect all seed heads you can!

rspb or something like that as the nature needs people like you with wild gardens especialy if you let them put some bird boxes up etc . be nice to have a natural pond in there to for tadpoles etc .

grass in itself if left supports a certain amount of wildlife surley and what people call weeds like dandylion . i dont think youl need that many seeds as it will happily go wild on its own .

i think its more giving the right situations like said pond, wild trees ,maybe some sandy parts etc . id definatly ask about rather than pay out .

I thought I had found something interesting for you today, Ricky, in an Italian DIY shop (a bit like B & Q), but I realise now that it's every bit as expensive as the seed you can buy in the UK (about €10 to seed 5 square metres) . A German (I think) company sells about six different types of wildflower seeds (damp conditions, hot dry conditions, etc.,) and I went on to find some for sale at a reduced price on Italian ebay, but actually being posted from Sheffield! Blumen doesn't appear to have an official presence in the UK, and isn't for sale on ebay UK. Explain that one if you can! Have you tried Amazon.uk?