Okay,here’s the problem-I’m adding up the costs for a 4x8 layout(based off the rock junction). I have everything but the track,dcc and wiring. I am planning on using HO 83 and running two modern switchers. Can y’all give me a rough estimate on what the cost might be.
If I left anything out,let me know:)
It looks like you have a handle on things. a DCC setup will cost a bit, best to look up the prices for Digitrax,NCE etc… wire you can get fairly inexpensivly.
ask yourself, is the 4x8 going to be it or are you going tbreak it down later . I just did and am happier with a 2x24 shelf layout.
Another consideration is your finances, this is where you might get your wife/ partner/ financial advisor interested. it can help to loosen pursestrings if needed.
best of luck and keep em rollin
Around $500.00 USD
Go to a few online seller’s websites and check prices for various components.
For a DCC starter set - figure about $200-250 as a ball park figure for a command station, throttles and a couple of decoders. http://www.tonystrains.com/productcompare/dcccomparison.htm
For switches and track - count number of turnouts, look up the cost of whatever type you are using, using e.g. http://www.modeltrainstuff.com/HO-Scale-Code-83-s/1465.htm?searching=Y&sort=13&cat=1465&show=400&page=1.
Atlas turnouts will cost you about $15-20 per turnout, Pecos (with sprung points) about $25 per turnout. For a track plan with 10 turnouts - call it another $200-250.
Then it depends on whether you are using flex track or sectional track for the rest, and how much track you are trying to squeeze into your layout.
Wiring - petty cash compared with the rest.
I would not be surprised if the initial cost runs to about $6-700 or so. Long term cost over the years? Probably quite a bit more 
If money is a big problem and you need to keep this very inexpensive, consider using DC instead of DCC, having a simple track plan, and be prepared to live with more scratch built scenery, structures, building kits instead of ready to run cars, making your own turnout throw mechanisms and so on
Make a list of what you need, get a calculator, add it up?
…or you can trust me. It comes to about 12K [:-^]
I have a 3.5 foot by 5.1 foot HO scale layout and I spent about $300-$350 easily building it and DCC-ing it with the cheapest DCC unit there is…the Bachmann EZ Command DCC system.
That would include the framework, legs and wheels, the extruded foam “table top”, the track and 8 snap switches, and the DCC unit and the buildings, and a loco or two. And the layout is not scenicked yet as I plan on moving so I did not “finish” it yet so I can take it down. I also want to expand it but may be better off starting again once we have a house to put a more permenant larger layout in. I would dearly love to have a 4x8 but have no room for that nonsense now.
I have spent more on RR cars and locos {have 12 of them now} so about as much as on the layout itself at about $50 per loco for Bachmann DCC OnBoard locos.
This is just to give you an idea. I have a 15"R inner oval interconnected to an 18"R outer oval, with a 4 spur mini yard and 2 spur engine servicing facility inside the inner oval {hence all the switches}…
Considering a model railroad is never finished (say some…), the cost is infinate[;)]!
Just buy what you need as you need it and budget will not be a problem.
sfb
As a real rough thumb rule, I’ve always used $25 / sq ft exclusive of power and trains.
This would put you at around $800, plus $250 or so for DCC and another $2-300 for decent locos and rolling stock.
However, this is just what I tell people who say, “I’m thinking of getting into the hobby, what does it cost?”
If you already know what your future layout will look like, why not create a bill of materials and price it up? OK, for stuff like ground foam and landscaping materials, you may not nail it on the head, but you’ll be in the ball park (you can always estimate this part at, say, $5 / square foot). The advantage to this approach is that it allows you to shop for the best prices, and to know what you need so you can take advantage of sales.