I would suggest spending a little extra and getting a decent pair of shorts/knickers. I know it may seem like a gamble, but in my opinion, a cheap pair of cycling shorts can almost be as bad as not wearing a pair of cycling shorts. Cheap chamois + cheap material often equals bad fit. It's one area where I definitely think you get what you pay for. Instead, look for a good deal on eBay or for a sale on Campmor.com, REI or Sierra Trading Post. There are lots of good brands, but you might start with Pearl Izumi or Terry.

And, no, the no underwear thing doesn't gross me out. If it saves me from a saddle sore or chafing, then I'm all for it.