Thanks for posting your question.
You are correct in that there have been more sales (since Sept 1) in the price range of $200-$300k in the Sandpoint area than in other price ranges. 32 sales in the $200s, 21 sales in the $300s, 12 sales in the $400s, and 12 sales in the $500s. A big factor is the conforming loan rates versus the jumbo rates. Conforming loans can be offered for loan amounts up to $417,000, currently with 30 year fixed rates under 5%, whereas jumbo loans above this amount are currently in the 8% range. When you get into the million plus market, many buyers are paying cash so it doesn't make as much difference. Its important to note however that your property at $499k could still fit a conforming loan as long as the buyer put at least $82k down.
Its interesting you should contact me, as I have a serious buyer coming to town in a few weeks who is looking at property in the $400 to $600 price range, with 5 acres, etc as described by you. This particular family is interested in newer construction, and I don't know where or what your home looks like. However the point is that there are indeed buyers around in each of these price points. I have actually not seen many modular homes sell recently. Most of the lower priced sales have been for single family homes in town.
If you would like to contact me with the addresses and information on your two properties, I will be more than happy to give you an unbiased market analysis and recommendation for each place. Then you can make your own decision based on facts and your particular situation.
Feel free to call me directly at 208-304-5665, or visit my website and fill out the information for a Market Analysis. Here is the link to that section: http://www.sandpointresortrealty.com/market.html.