There are many many other expenses other than the cost of the home and land.
I helped an investor with a land home package. We found a repo newer double wide home for 15k (75% off the price if new). We got him a really good deal on the land at 20k with pad in place. At the end of the project (permits, moving, set up, utillities, ect) he had $65k total invested.
The "little things" add up fast.