Before you resign youself to selling ... did you talk to any of the excellent brokers on the forum about refinancing and getting a lower interest rate?
As advised, your repayments seem to be really high in the current market. Even if you go on interest only repayments, and put all your surplus towards the credit card debt (should always pay down your highest interest rate debt first).
Why are you, or your wife, not able to look for employment? Something as simple as dog walking/minding, newpaper/brochure delivery, lawn mowing or expanding your online business to include more "in demand" items etc ... there are endless options
selling fees on 250k property will not be 10k and offering to pay say 50/week over market rent would likely have the same effect of enticing an investor
i just think it makes absolutely no sense for someone who is under severe financial pressure to sell a property for 30k under market value
Why not try to reduce your cost of keeping your own house to the cost of renting? Sure, if you are renting you don't have to pay rates, house insurance etc, but the rent will continue to increase and you may find you have to move again and again.
What about taking in a foreign student for a short term until things improve, or try those things Lizzie and others have suggested. I'd hate to be at the mercy of a landlord when you have troubles enough already.