Our house has been on the market for months now and because of the economy we would like to take it off the market and keep it. Should we offer to pay our realestate agent any money for the time and cost he as put into it (re: advertising, etc)?
If you're not contractually obligated to do so, it's totally up to you and as far as I know, not a standard practice. Anything they have done for you is a standard cost of business as they will always talk to, list and show more hosues then they will ever sell.
If you really wanted to do something for that person's efforts, send them referrals. When people do bad things to other people, they tell everyone they come across, having people do the same for positive experiences, although not rare, is not done with the same energy as passing on a bad experiences and professionals such as realtors, brokers and salespeople depend on referrals.
Unless your listing paperwork provides for early withdrawl fee's or compensation, the answer is No. It does cost brokerages a lot of money to promote a given property and that money is lost if the property is either withdrawn or just doesn't sell, part of the cost of doing business in real estate.
While my answer is general there are numerous brokerages accross the USA that charge any number of fee's not only for early withdrawl but in some cases an up-front listing fee to offset advertising costs. In this unsure market of today no one knows the probability for a given property selling and it will probably be some time before we see some resembulance of the "old days".