Yes - Lexus Parts Now is fine, they buy from whatever authorized Lexus dealership will give them the best deal and the fastest - I have used them many times - other dealerships that are actually Lexus dealers can be a day or so faster in some cases:
example prices on part# 89422-20010 Engine Coolant Temp Sensor before shipping:
sewell is best for large orders so you can save on shipping, and you can get a discount by being from club lexus!
sometimes! - but not always - note the two examples above - one part ebay puts a whoopin on them and on the tranny mount, Lexus of South Atlanta wins - Sewell is consistently one of the cheaper sources with our discount, however, and they have very nice parts diagrams!