Is $10,000 to reline the chimney flue with 6" stainless steel a fair price?

I live in a 2100 sq ft house in Upstate NY, built in 1960, with the original natural gas boiler and a separate traditional water heater. The boiler is 150,000 BTU and 80% efficient. I have been considering upgrading to a higher efficiency boiler due to the age of the current 65-year-old unit, but have been reluctant. Recently, a tree fell on my chimney and crushed the flue for the furnace and water heater. I'm having difficulty getting masons for repairs until next year, but flue lining companies are quoting around $10,000 to reline it with 6" stainless steel. I feel that $10,000 is a significant amount that could be put towards a modernized, direct-venting setup instead. I hope insurance will cover the chimney repair, and I'm considering discussing an upgrade to the boiler/water heater with my adjuster. I'm interested in Weil-McLain, specifically the GV90, as it seems potentially more reliable than other combi units. My manual J calculation suggests I need between 90-100 BTUs. I've already upgraded windows and am adding exterior insulation as part of residing the house. I'm looking for suggestions on whether to proceed with the chimney relining, get a quote for a Weil-McLain system, or consider an indirect water heater or other setups.