For Paulsons that are not available at retail, eBay is the way to go. I've bought lots from various sellers. As longs is it's someone who has a reasonable feedback rating, you should be OK. My advice is to pay by Paypal or credit card, not money order or western union.
But for Pharaoh's, I would order directly from an online retail site -- Holdempokerchips.com (or there are others). This is much easier...
- you can get exactly the chip breakdown you want,
- various types of cases,
- excellent fast service,
- don't have to wait for auctions to end,
- pay a variety of ways,
- fast shipping,
- cards or other merchandise at the same time,
- etc.
You don't have to get what's in one particular auction. And they are a good supporter of this site.