when looking, i visit tooltopia.com, amazon.com, and ebay.com. i often also google what i am looking for. on rare occasions, usually on some esoteric thing, i will find it cheaper somewhere else, but usually the best price is one of those three.
i order from cripedistributing.com regularly too. often i will find something i am interested in on their ebay store, and then i will just shop the store for other stuff that catches my eye. i buy directly through their web site, rather than on ebay. i assume it is cheaper for them, and they give me a discount and great pricing on shipping. if they have it on ebay, and not on the store, i note what i want, and email them. Bree, the person who always seems to answer my email, gets it all added to a cart, and they price out the shipping. it is not instantaneous, but on the whole it does not seem to take them any longer than anyone else i deal with on ebay.
amazon wins on quick free shipping, and offering the option of third party sales. often if i see a third party there i will check their web site too. usually i just order through amazon, because it is just easier (i already have an account, they will help me deal with issues, etc).
tooltopia is great, and they have great pricing on some things, but i admit that the 75$ free shipping floor is harder for me to fill than i thought it would be. i seem to get stuck around 50$ for a long time, and then it goes up to 200$. their daily deals can be good, but, again, shipping . . . . .