will a receiver upgrade make a enough difference

My experience is that _any_ speaker, except perhaps one that's broken already, will let you hear an improvement in upstream equipment.

To try this out, maybe you could take your speakers in to a store which sells really good stuff--like maybe an Audio Refinement multichannel preamp--and see if they will let you hear the difference when you go _way_ up the scale.

Then decide if a receiver upgrade will make a big enough difference. You may discover you prefer to wait until you can afford to take a giant step.

If your older Mitshubishi doesn't have DD or DTS, you'll notice a big difference when watching movies with those formats. If you buy a new receiver with prologic II,you should get more out of your music and television.

I think that most of the Japanese recievers sold today sound alike (and not good at all) regardless of cost. Listening to new front end components (dvd players etc.) is a lost cause through most of the mid-fi recievers sold today; most of them just do not have the resolution to hear a distinct difference and it can be difficult to turn off all of the effects. If you were to upgrade your reviever I would definitely look into the B&K products. These components sound more like hi-end components than mid-fi and are priced within many budgets. I like them much better than the current Rotel components that I have heard. Changing the speakers will make the most positive difference in sound at this point. If you are not set on a new reciever, I would look into some better speakers first, then the reciever, and finally the dvd player.

You don't say anything about owning a dvd player? You will need one. You could get the outlaw audio receiver for $499, it has pre out/amp in for all channels and crossover from 60-200hz for sub out. Down the road when you get some more cash you can just get a couple of their little monoblocks for more power to the front channels. Just going to DD/DTS will be huge increase in quality of movie sound over pro-logic, at $499 it makes a nice pre/pro even if you don't count the 6-65 watt amps you would have. The nice thing about pre outs for all channels which is very hard to find in a receiver in this price range, is that you can add as many high power amps as you think you need down the road and use the receiver for a pre/pro. On the other hand you don't say how much money you have to spend right now, if you have much more cash to spend, there are other ideas in other price ranges. outlawaudio.com has some of them on their web site.