Egor:

I used to live in an apt. a long time ago with tiny electric tank..i think it was like 30 galloons.  So to take showers of appropriate length with the numerous women that kept visiting my apartment, i had to bring the ratio of hot/cold to like 10/90.  This was accomplished by taking apart the thermostat on the elctric heater and removing the safety (stopper) that prevented the thermostat from being turned up higher.  I figured anything below boiling would be ok since there is a safety valve.  I did this gradually over time, until the valve began releasing steam and water like a dormant volcano, at which point i turned it down a little and lived that way for 3 years filled with erotic escapades and pleasures, the extent of which cannot be fully conveyed in a forum setting.

TMI, irrelevant!  XD

Monday morning I had a plumbing issue in my house (burst pipe) and two Mr. Rooter guys came to fix it.  While they were there, I asked them about tankless water heaters.  How much they cost, etc. The guy said it all depends on how many bathrooms (with showers) I have.  I said that I wouldn't need to cover all bathrooms at once, because never ever will all bathrooms be used at the same time.  In fact, there's two bathrooms with showers that I don't think anyone has ever showered in (one of them is the basement).  The guy said that doesn't matter.  Legally, he has to put in a big enough tankless water heater to cover the possibility that all showers will be used at the same time.  He said that it is a building code, something to do with the law that dictates this so that if I sell the house, there's some kind of 'standard' so the new owners won't get stuck with an under-performing water heater (how this law applies in this case).  So then he quoted me a price, ranging from low to high.  He said the range is based on variables that he would have to look into more closely because with a tankless water heater certain pipes need to be made of certain materials, etc, so the installation price would depend on how 'compliant' to tankless I may or may not already be.  In my case the quote was $4500 to $5500, with $6000 being the absolute max and that's if I'm a worst-case scenario.  This is for 5 showers (5 bathrooms with showers).  He said that it would probably take 10-15 years in energy savings for this investment to materialize.  He said that really, it's not a good investment but just a luxury.  We have two large capacity water heaters at home which probably cost half the price of the above quote when the home was built.  So had the builder put in the tankless from the beginning, it probably could have been cost-effective or at least worth paying for the luxury.  In my case, since the water heaters are already there, it would be stupid to go tankless, especially since not that many people are always showering and really, I've never run out of hot water.  Oh, one more factor:  the Mr. Rooter guy said that the lifespan of an average water heater is about 10 years, whereas tankless water heaters have lifespans of 20-25 years, sometimes even more.

Ok, that's the 'proper' channel of finding out.  The Mr. Rooter, reputable company, way.

If you want the 'Russian'-style price, here it is:  one of the builders for the house who was building the basement for us also answered my question about tankless water heaters (about 6 months ago).  He said he knows a guy who installs tankless heaters from China, about average quality and one for my needs would run me about $2000-$2500, installed.  Of course that would probably be an 'under the table' deal and this setup most certainly wouldn't cover all 5 showers at once (which I really don't need).

 Hope this sorta gives the answers you guys were looking for :)

I think it makes more sense the smaller the house, and the fewer people are living there.  The real cost savings comes from not having to keep a huge volume of water hot and mostly unused 24/7. 

By the way, I noticed an energy-saving feature I didn't even know about in my water heater..  It keeps the water much hotter when it sees "activity".  If no one uses hot water for 12+ hours, it keeps it much less hot.  Problem with that, is in reality - level of activity is not a good predictor of how much hot water will be needed all at once, unless you are on vacation or something (in which case I can just turn it down myself).  And I can't turn this feature off.

Thats what started me thinking abt tankless.. 

Thanks, II!

PS 5 bathrooms. . . That's intense. That's insane.