Paradigm makes some good quality speakers, but so do many other companies. I imagine the local high priced audio store you mentioned probably had them set up in a listening room. That can be a better environment to audition speakers than in an open environment like Best Buy or Circuit City where you are dealing to all the noise from all over the store. I would suggest you listen to as many different kinds of speakers as you can. They all sound a little different so only you can tell what sounds good to you. Yes, different receivers will make speakers sound different. Ask to listen to speakers run through different receivers as some are called bright/neutral and all sorts of other descriptors. The sound also depends on what sound processing the receiver is set to, Dolby, DTS, jazz, rock, game mode, 5 or 7 channel stereo, and the list goes on....
And don't worry about a better one coming out tomorrow. Something better always comes out, but it takes longer than a day

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Set a budget, and buy what sounds good to you within that budget. You're going to be listening to/enjoying your purchase for a long time so take your time, don't make a decision based on the one set of speakers you listened.