Hi
I haven't finished my install, but it looks high from what I have done so far. I am installing to a mobile home. Down-draft forced air and a propane hot water heater.
I bought a 6048 standard model. (No special colors, stainless, or dual-fuel) for roughly $7200 delivered.
I have made my own slab. Slab was built to Classic's sizing from the site. $30 for lumber 2x6's, had enough nails hanging around. 24 bags of quikrete at $5 each = $120 Rental of a compactor and cement mixer = $88. So the slab was $238.
I purchased my own wire and have installed it in the house to two spare breakers. 2 coils of 12/2 150ft at $130ea = $260
I installed a second thermostat already. $20.
So far my total is $7718.
I still need it installed. Thermopex and the 2 heat exchangers.
I am installing about 120ft from the house. The ditch is being dug as part of other work being done around my house so not sure how much the ditching alone would cost.
If thermopex costs me $15/ft. (Don't know the cost yet, hoping around $7) it would be $1800, if each heat exchanger was $500 and labor was $1000 it would still only total
$11518.
My last numbers are extremely inflated I believe, I expect to come out under $10000 and that is for a larger boiler than you are looking at. I would think that you should easily be under $10000. The 175ft of pipe is your biggest expense besides the boiler.
I hope this helps. This Friday when I am installed I can get you some more substantial numbers.