If you know anything at all about buying bed sheets, then you realize that buying nothing less than a 400 thread count is not the best investment you can make. The sheets will be thinner and they will be much more likely to pill and wear out sooner rather than later.
Of course, 400 thread count sheets are generally more expensive than a 200 or 300 count, and this is especially true if you are buying genuine Egyptian ELS cotton sheets. That's because the quality of the fabric is going to be so much better, become softer and last much longer than standard cotton.
You can buy Egyptian cotton in much higher thread counts, 600 and 800 also being quite popular for those that really like extra luxurious sheets. For most of us, a 400 thread count is just fine, especially if you are on a budget. You can still get the luxury with a 400 thread count without busting the bank.
The brand of bed sheets you buy can also be a factor in how well the sheets are made. I visited Luxury of the Pharaohs and I was amazed at how much there actually is to know about bed sheets in general and also Egyptian cotton and what that really means!