I think the answer kinda depends on how far you're going with the remodel. I would think that removing the tub would damage the tile surround - and if you have a tile that wouldn't be easy to match, that would pose a problem. On the other hand, if you're already removing the tile surround, it might be worth it to replace the tub.

In the interests of recycling, I say if you have a sturdy old cast iron tub, and/or if you're not planning to do anything to the tile surround, keep the tub and have it professionally reglazed. I think that'd cost a few hundred bucks. On the other hand, if it's fiberglass, I don't know how refinishing on that type of tub works - might be best to replace.

If it is a enameled steel, fiberglass or acrylic tub, I say replace it. For a rarely used tub, a $100 enameled steel tub will hold up fine for occasional use.

If it is a cast iron tub, fill it with hot water and pour in about a quart of bleach. Let it sit for a couple of hours or overnight. Shut the door and turn on the exhaust fan to keep the fumes down. Then, let the tub dry and apply a coat of automotive paste wax and buff it out.

What we found is that resurfacing looks good but is a bit grainy and never comes back to the original feel and shine. If there is nothing special about the tub that you want, I would replace it. It won't cost much more.

When we remodeled the designer said to consider a steel tub vs. a cast iron. Much, much cheaper and you would never know. Looks great to me.

Thanks for the suggestion. We are starting from scratch. Every bit of the old bathroom (fixtures, vanity, tile, etc.) is being replaced. We've decided to replace the tub as well!