My original setup (roughly 3 months ago):
$1.99 Wally World clearance plain weave nylon (almost 3oz/yard but light enough and durable), 4yds, gathered end, tied off with sheet bend using extra webbing (see below): $7.96
15ft x 2 Poly webbing from ratchet straps: $8+getting those **** hooks off
Two walmart 'biners - 300lb rated: $5 total
Tarp: Either 8x10 standard poly tarp or Outdoor Products 5x7: $10
Total price was $30.96 + tax
if you want a bugnet you can pick one up for ~10 or DIY and you can pick up a 30° sleeping bag for around $30.
These two (optional/winter) accessories bring the total to 70.96. Not under 50 but considering how old this thread is its pretty close.
What's the weight of that setup, packed and ready to go?