You can buy a built wheel from Coker for $118 + $65 shipping: http://www.cokercycles.com/accessories/coker-36-inch-rim
Building your own from new parts costs about the same. 36" spokes from UDC are expensive; they are much cheaper at UDC UK but you need to put together an order with enough savings to justify the shipping costs.
You might be able to find someone on the forums with an old steel 36" rim they are no longer using.
Are you still riding the 36" you bought on the forums back in February? That’s about the least expensive 36" wheel that you’re likely to ever find. If you can justify an upgrade, say like buying a new aluminum Coker wheel for your uni, the steel wheel you currently have would be perfect for a project like this.