whipped dog has a pretty good rep over at straightrazorplace. also look up lynn abrams over there, he is one of the gurus of modern straight razor use. There are bargains to be had, but far more crap on the market as it has seen an uptick in popularity from a sort of hipster sort of style thing. The good thing is that there are lots of good old razors around, and the big companies are able to make good razors at a volume that lends to value. Ebay razors probably have vegas table odds, so unless you have a gambling habit I would stick to places with reputations to maintain.
No disrespect intended kn4wd, but I would suggest that IanShane look more towards some of the SPR honemeisters. (and if you want to get into it, there might be a great place to advertise if you haven't already, I've been away from there for a while, more than a few guys have started building rep there on a pay-for-shipping basis) The only reason being that if Ian wants to learn to shave properly, that means eliminating as many variables as possible, and there are some guys over there with long term public profiles. Again no disrespect, but you are just some guy in the internet.
Ian, the first thing you should do is get a decent brush and good shave soap. (lots of different options to be had. mitchels wool fat is a good baseline to start from, I really like DR Harris and taylor of old bond street) Read around here for lots of options, Golnick did a great list of soaps a while back. Get started with that, even if you don't switch to straights, the soap is far better for your skin and wallet even if you stick with cartridges. And since lather is one of the key skills, might as well start on it now while you get your straight organized. good prep means good shaves. Mantic59 has some great youtube vids on shaving with a DE and making lather. good starting points.