I have bought more than 50 items on indiaplaza.com and I can confidently say that they are reliable.The only drawback is a poor customer care in terms of calls being put on hold and delayed replies to emails.The site is a lot cheaper than even flipkart.com and they always have a discount coupon for the products which further decrease the price.
If they improve on the customer care side, Indiaplaza can be a strong competitor to many other sites.