Best Buy has 2 sticks of 512MB DDR cheap; try your B&M if they're not online!
Crucial 512MB PC2100, $55: http://www.bestbuy.com/site/olspage.jsp?id=1051384690377&skuId=5310889&type=product
Currently OOS but I picked one up at my local BB for that price!
K-Byte 512MB PC2700, $70 - $30MIR = $40: http://www.bestbuy.com/site/olspage.jsp?id=1051384692819&skuId=5319979&type=product
Crucial 512MB PC2100, $55: http://www.bestbuy.com/site/olspage.jsp?id=1051384690377&skuId=5310889&type=product
Currently OOS but I picked one up at my local BB for that price!
K-Byte 512MB PC2700, $70 - $30MIR = $40: http://www.bestbuy.com/site/olspage.jsp?id=1051384692819&skuId=5319979&type=product