You indicated that you tried to refinance last summer and "no one was able to find truly suitable comps". As far as refinancing is concerned, the bank or mortgage company will ultimately use an appraisal to justify the refinance amount and Appraisers (as well as RealtorsÂ®) know how to adjust the values against the comps that are avaiable to come up with the right value for your property.
As previously stated, the fact that you have 8 acres does not necessarily add a lot of monetary value to the property, unless it is useable (subdividable) land. Yes, there may be 1 buyer out there that values that privacy and space as much as you do, but that is not the case for the general market of today's buyers. Similarly, there may be 1 buyer that would value the improvemenrts you have made as much as you do. Unique properties take longer to sell, because you are waiting for that 1 unique buyer. You may also have to consider that some of the improvements you put into the home may not be appreciated by others (potential buyers) at the same level as you value those items.
Unfortunately, the real estate market at the moment is not conducive to making a profit on a property in a short time period. Homes that were purchased in the last 2-3 years are not selling for what they were purchased for, much less for any significant improvements that have been made.
My best suggestion would be the same as has been mentioned in another "answer" - if you don't need to sell right now, don't. Enjoy your home and wait for the market to rebound a little. In time, the market will come back and you will be able to sell for what you paid, plus the extra you have put into the home, and with some profit. Be prepared to wait several years for the market to rebound enough for you to recoup and profit from the home you built in 2008.
If you need to sell now, find a RealtorÂ® you can trust to take the very best care of you, and that you can work with "personally" during a very difficult transaction. Trust the RealtorÂ® who will be honest with you and who is more interested in taking care of you than in "getting the listing". Anyone can list your property for a high price, or a low commission, just to see if they can get some business off your listing. That is not taking care of you and your needs.
Hopefuly, you can make things work so you can wait a few years.