this was offered to me I thought the price was too high
This depends on your location and the brand and type of installation if it is a change out then it can be roughly $5,000.00
Please let me interpret: 70,000 BTUs @ 80% AFUE - that is the question? Oil or Gas (propane and gas are within $50 of each other if there is any difference at all)? First, that is a small boiler as these things go. Second, that is also an old-technology boiler as 80% is considered pretty inefficient these days. So, it will be fairly cheap. You can buy a conventional cast-iron gas boiler such as you describe for less than $1,500 delivered. If you go to an off-brand and/or a steel-jacket boiler you can pay as little as $900 for a new unit. For a good brand-name boiler such as Weil-Mclain, Hydrotherm, Slant-Fin or similar, figure in the $1,200 range. For an oil-fired boiler, same general parameters as above, figure in the $1,500 - $1,600 range. The above is for new units, but *NOT* installed. Depending on the complexity of the system and the amount of demolition required, access and so forth, installation can be anything from a 3-hour to a 3-day job. Conventional boilers replaced by conventional boilers tend to be on the shorter end of that range. I have spent 3 days replacing a lead-lag, dual-system mare's nest with a single properly sized high-efficiency boiler and less than 2 hours replacing a conventional, very small boiler with a similar new unit. All based on US prices.
