I can't find it right now but I read an article recently on Physorg.com that talked about the cost of purchase and installation in Germany compared to the US. The cost of materials didn't differ much, the extra cost for us comes from all the bureaucratic red tape - licensing, permits, approvals and on and on. As I stated, the estimate is right inline with the national averages for that size of a system. Yes you can go out and buy the parts yourself but what are you going to do when you tie it in to your house? Are you going to run all new, dedicated electrical wiring so that you have 2 outlets where you used to have 1 and label one for your grid and the other for the power company? Last time I checked you have to get the power company to sign off on your installation if you're just tying it to your current electrical system which is consequently tied to their system.
On top of that, what are you going to do if you ever have an issue with your house and your home owners insurance finds out and drops you for not having a licensed professional install the system, have the necessary permits approved etc.? You can mikey mouse your system all day long, even if you know what you're doing but just be aware that you might be setting yourself up for a lot more costs than just a professional installation and possibly even fines, fees etc. from your city or county.
$.60/watt is on the extreme low end, I only found prices that low when you bought enough panels to equate to 5-7kw of power so thinking that you're going to buy a quality (read quality AND good warranty) panel for that price is probably unrealistic. Finding them for $1/watt is still probably a stretch for quality and low quantity. If you want a good price, install a 40kw system which can drop your cost per watt down to $2/watt but for small installations you're going to pay more per watt.
For anyone thinking of even attempting to do this completely DIY as in buy the solar cells, the tabbing wire, solder them together, build the frames, encapsulate them etc. GOOD LUCK! You can do it but by the time you get done it will probably be more expensive just for the materials not to mention your time spent, losses from the learning curve, losses from picking the wrong materials, the headache of learning on your own dime and the worry that your product won't last even 5 years. Even if you only screw up one panel and then only have one more panel that screws up in 5 years, you've already brought your cost per watt up significantly even without counting your "free" labor. I'm not sure anyone here was contemplating it but I just thought I'd share, I've looked into it, researched the different encapsulation materials and methods which is where your longevity come from and there is no cut and dry answer as to what's the best to use and it's still more expensive than pre-made panels.
If you want solar but can't stomach the retail installation cost, find yourself a local electrician or general contractor who might be able to do it cheaper than the main guys but do it RIGHT (read permitting, power co sign off's etc.) Don't risk your house, don't risk your install, the bureaucracy sucks here but you're not going to beat it by being super cheap.
One alternative you DIYers might consider is buying the stuff and installing it yourself if you think you're capable but run dedicated electrical lines to a particular room for your mining and that way you bypass the power co sign off and possibly some permitting. I would also advise a free standing installation in the yard as opposed to the roof to try and avoid some serious permits. Depending on how much of a liberal nazi loving area you live in you might get issues about "unsightliness"...
Check for federal, state and local rebates and incentives as Cochese suggested, this can offset a large portion of the cost and also check with your power company about them buying your extra electricity. They don't do that where I live but some places do which might be an incentive to over-size your install to get a faster ROI. Sorry for the rambling
