Go here:
http://www.myprotein.co.uk , click on the price matcher and type in w*w.bulkpowders.co.uk. (without the star obviously)
5kg Whey Protein Concentrate 80 @ £31.95
5kg Ultra Fine Scottish Oats @ £9.89
Now for sweetening and flavouring there are a few options open to you.
The cheapest and unhealthiest:
1kg
Dextrose @ £2.95
Nesquik - get from supermarket any flavour you want.
Healthier but more expensive:
2kg
Palatinose @ £11.98 - you could try 1kg but it's only half as sweet as dextrose.
Cocoa Powder - get from supermarket, Green & Black's organic cocoa powder is awesome
Another choice from Tesco instead of myprotein is the oats. Tesco sell 750g of organic jumbo oats for about £1.20 but obviously these aren't as pleasant as the fine ground ones from MP, so it's upto you.
If you followed all that you'd end up with:
26lb of Top Quality Weight gainer for about £50 - cheap
or
28lb of Top Quality Weight gainer for about £60 - dearer but best.
If using MP for first time then using someones code (like mine
MP5500) would save you 5% off your first order.
Use the money you saved to pay the little bit extra for some Channel Islands Gold Top milk (unhomogenized) to mix it all in and you've got a fantastic weight gainer. These choices are
FAR healthier aswell as being much better value for money.