Update
Thanks, everyone for your input. Decision was reached today. Process went like this:
Bid 1 - Company associated with Costco. Rep came out on Monday, took about 1.5 hours to review equipment, discuss performance of current system, listen to our concerns and talk about our options. Sent an email later that night with estimates for 2 systems. Option 1: 3 ton single stage AC and 80,000 BTU gas furnace - cost $8900. Option 2: 3 ton two stage AC and 80,000 BTU two stage furnace with variable speed blower - cost $10,200. Overall impression was that they were fairly knowledgeable and, as a large operation, would be able to get to it within a week. For some reason they really wanted me to know that the owner ran a Christian operation.
Bid 2 - Company recommended by friends. Rep came out Tuesday, took a quick look at the current install and wrote up an estimate on the spot. Single stage AC, 80,000 BTU single stage furnace - cost $7700. In and out in twenty minutes.
Bid 3 - Company heard about through ads. Rep came out Wednesday, Took a long look at the equipment, took tons of pictures. Asked many questions about current system satisfaction and explained how the two-stage options would improve comfort. Very responsive to my questions. Suggested that the current furnace was likely too big but that he would have to do a load calculation
facepalm
to be sure. Said he would send me the estimate by email after he completed the calculations. Came back with Option 1: 3 ton single stage AC and 66,000 BTU two stage furnace - $6500, Option 2: 3 ton two stage AC with 80,000 BTU two stage furnace with variable speed blower - $7700. The down side is that it would be 2 weeks before the install.
All equipment is comparable, high quality stuff.
So, after DW and I discuss this, I call Rep 3 back and say that we will take his Option 2 and we set a date for the install.
THEN a different rep from Company 1 calls me to see if we have made a commitment yet. I tell him yes, that we are going with company 3. HE asks why, so I tell him that $2500 is a lot of money and that we would be happy to suffer for a week to save that kind of cash. He then offers to drop his price by $2000. THIS REALLY P***ED ME OFF. I told him that I would not be comfortable going back on the agreement that I had already made.
What bothers me most is that I told all three of them that I was getting 3 bids and that they should make their best offer. These guys seemed to think that they could squeeze an extra couple grand out of me, if I wasn't smart enough to do my legwork. Didn't seem very Christian to me. I'm thinking about complaining to Costco - I can see where a number of people might not get multiple bids because they would assume that, if Costco partners with them, then the price must be good.
End of Rant