1/20 Gold Pandas and 1/20 Gold Maple Leafs sealed in mint plastic, around $92 to $98. A little smaller than a dime in size. Many large dealers carry these so I would buy from them, Apmex and Modern Coin Mart. If cheap gold is what you would like to buy (buying on a budget) them I would buy the 1 gram pamp suisse gold bar, around $53. About half the size of a postage stamp.
I bought a certified PCGS XF45 1851 quarter eagle for my type set that set me back $250 which I felt was a really nice price. If you do some hunting I'm sure you could find a 19th century quarter eagle for $300 or less. Certainly some gold dollars could be had even less than that. But the most economical is a modern 10th ouncer.
Here are a couple fairly decent and cheap $1 gold with buy it now. One even has or best offer. You could do better if you take the time to bid on auctions though... http://www.ebay.com/itm/1857-Ty-3-1...82?pt=Coins_US_Individual&hash=item1e8feebe6a http://www.ebay.com/itm/1851-1-GOLD...41?pt=Coins_US_Individual&hash=item3a948184a9