For those Er'd or near, what are your estimated replacement costs for:
Roof
Furnace
Water Heater
Plumbing
Electrical
Structural
Are there any other major replacement items you've encountered and their costs.
A general point first: if being wrong on one of these issues will make or break an ER, then the plan is either undercapitalized or not flexible enough. For example, if a furnace replacement starts at $2000 but "new issues" drive the price up to $6000, that shouldn't ruin a budget. As Calmloki & W2R have indicated, maybe the key is not so much the focus on the cost of individual items but rather figuring out how much per year (on average) will be spent on "home repair" and "home improvement".
I think part of the price consideration should be how much time you're willing to spend on maintenance. The lifespan of every one of these objects can be greatly lengthened by proper care. So perhaps one cost is the $20 annual subscription to a magazine like Family Handyman or a home-care course at a community college.
Another issue is how much you're willing to invest up front. A cheap composition roof, 50-year wood shakes, or 100-year metal? A used water heater, a new energy-efficient water heater, or a solar water-heating system? Big price difference, and the payoffs depend on how much time you'll be spending in that house.
A final consideration should be how long you're able to delay a repair. You may need a new roof, but its life could be extended a couple years by various cheaper repairs while you adjust your spending/budgeting to catch up for the bigger expense. And if know the condition of a component well enough to project its replacement 5-10 years in the future then you'll rarely be surprised, and you'll have plenty of time to tweak spending over the next five years. But if your ER decision depends on predicting the precise year in which you have to make a major expenditure over the next decade or two, then you may be living a little too close to the edge.
But here's my experience:
Roof-- $10K for composition shingle, $25K for cedar shakes.
Furnace-- sorry, no idea.
Water heater-- $100 used from Craigslist, perhaps another $50 for parts, a morning to make the swap. An anode rod every 4-8 years. I've gone through this drill this 3-4 times now and used water heaters are plentiful.
Plumbing-- Rex Cauldwell's "Plumbing a House" is another essential reference ($30?) plus $100/year for tools/parts. Maybe another $200 every few years for a really neat faucet or shower head.
Electrical-- Rex wrote "Wiring a House", too. EnergyStar ceiling fans can get expensive ($250 and up) but knowing how to fix your own again can probably keep annual expenses under $100/year.
Structural? A few hundred bucks on paint every 5-8 years? $500 for termite treatment or $2000 for termite repairs? Free mulch or $1500 for sod? Or, after a decade of planning & pricing, spending thousands of dollars to bring in a crew to rip out/replace a lanai and repair lava-rock steps?