Anyone remodeled their home into log or post and beam? Costs?

This is like asking if anyone has changed their dog into a turtle. Log and post-and-beam are basic construction methods, not decorative surfaces. You can install some fake elements here and there to suggest a particular feel, but you can't change the basic nature of the structure without knocking it down and starting over.

I don't see why one can't add real wood beams in a home and add log siding to exterior etc. I realize it wouldn't look like a full post and beam home, but it can sure help. Also wood interior can be added over drywall.

The really nice part of the post and beam "look" is the tall open spaces. Get the Tim Benson book if you have not already. You can look at thousands of conventionally built houses and you will not find one with the tall open spaces you are looking for. (Though you can get real exposed beams if you go for 200 year old farmhouses.)

To do timber frame properly, start with a moved, recycled barn or a fresh custom wood timber frame. Do the outside with structural insulated panels (for energy efficiency!)

An existing barn which could be converted to a house is another option - that gets you the beams. Around there they are all too close to the road.

Here is a link that might be useful: Barnsavers

I was asked to convert a 1970's Yankee Barn house into a Shingle Style house once. The owners had tired of the huge rough-cut posts & beams, the plywood T1-11 paneling, and the two story space that was impossible to effectively heat, cool and light. We left one beam exposed in a bedroom for old-time's sake.

The biggest problem was moving one of the posts. Another was the lack of lateral bracing in the original frame and panel system so we had to add some interior plywood braced walls bolted to the floor structures. The house is on the ocean so the owners were lucky it had survived as long as it had.

We managed to put more windows in the living room looking at the ocean with beams at the ceiling and a new master bedroom where the 2 story space had been. The bedroom had a great view of the ocean.

If you do build a P&B house, get a competent HVAC and lighting designer rather than depending on the builder. Be very careful how the windows are installed if you use panel siding.

If budget is a concern i would go with an already built home. Especially to save on things like septic and well, driveway, gardens, etc. There are tons of things you can do to create a timber home feel. A couple suggestions from me are as follows;
1. make sure the house you buy has solid framing and foundation. you will be adding weight to walls and floors and you want to start off right.

2. Use aged softwoods. They will be much lighter than oak barn beams. Much lighter and easier to work with.

3.consider splitting beams in half for use on walls and ceilings. Pole rafters can be used in the same fashion.

4.Brushed or planed barn siding works great on walls and ceilings. Paint the walls black or use tar paper before installing so any holes don't show white walls behind it.

5. Joists and old wall studs make great window/door casing.

I could go on for awhile as this is what I do for a living. I think you could really make something nice out of an existing house and it could be done at a slower DIY pace.

If you are in the midwest and need materials post again here and I can help you out with that or any design.