Dodge Caravan Infinity speaker problem

First of all a history...

Back in July I noticed I had a bad crackling in my front right speaker on my dash.  At any decent volume it would crackle or even go out completely.  I lived with it for about three months now.  I went to my regular car repair shop and they said it was probably the speaker and they ordered a new speaker for the dash.  They put it in and it did not work, but they luckily did not charge me and put my original back in...so they said it was the front right channel of the radio that was bad.  I then waited and finally replaced the standard cd/cassette radio with a Kenwood HU.  It still has the SAME exact problem.  So I have narrowed it down to the door speaker really, because that is where the amp is for the dash speaker and the door speaker is now starting to crackle as well.  The other speakers sound fine, other than they have a ton of bass which I am going to adjust down using the EQ. 

My question is this...where the heck can I get a door speaker, 5x7, for this with the amp built it and not pay an arm and a leg?  I mainly want to use it to diagnose whats going on with my system.  Idiot at local HiFi place wanted me to replace everything for 300 bucks.  BTW, I am disabled and can't do the work myself or else I would be.  Any ideas?

DigiMidget