Sorry Need2, not trying to pull away any business
I learned long ago (after spending an absolute fortune on supplements) that the best thing to do is contact your local dairy company.. I'm in Australia, though I'm pretty sure you guys in the US have plenty of dairy companies

Where do you think the supplement companies get their WPC/WPI/Cassein from? It's all a product of the dairy industry!
I tracked down our local (Nationwide) company, they are called the "Murray-Goulburn Collective", and sure enough they had big bags of protein powders just sitting around gathering dust. You think 10 pounds is a lot? I buy 20Kg SACKS at a time, unflavoured and instantised WPC/WPI/Cassein... I only buy protein perhaps twice a year, and I down a LOT of the stuff.. It makes me chuckle when I see people paying through their eye teeth for exactly the same product (except perhaps with flavoring) at a health food store.. (They are paying well over double what I pay...)
Seriously, if you are in this for the long term, it will pay you in spades to seek out a dairy company and at least ask them.. A simple phone call can't hurt, and could end up saving you an absolute fortune in the long run..
(My gym sells protein shakes [as do most gyms] with 30g of WPI. They sell them for $7 each. 30g of WPI costs me well under 50c! That's a $6.50 markup, and the shake machine never stops running, all day. Now that is a money spinner!)
Added bonus, if you buy WPC/WPI/Cassein, you can mix and blend the proteins to get exactly the effects you are looking for. A WPI Shake straight after hitting the weights is the best, as it is the most rapidly absorbed, but a Cassein shake is best before bed, as it is a relatively slow-burning protein, and will keep your body in an anabolic state for most of the night..
-c