So I've decided I want to swap out the chromoly fork and stem on my bike, I have a tapered headtube. A 1 1/4 headtube.

So my fork options aren't as broad. I found a nice tapered 3t fork in eBay for 169, which is lower than I've ever seen them. Now if I get that fork I don't need a new headset.

Or I can cheap out and use a headset reducer, use a more common straight 1 1/8 fork, buy a new headset and still come out under the price of the tapered fork.

Would I have a problem using the straight fork and adapter?

Or should I just get the tapered fork?

The answer probably depends on why you're replacing the original fork and what you hope to gain.

If the specs on the 3ttt are what you want, then go for it. Otherwise start by choosing a fork that meets your objectives, then figure out if it can be used, and what the related costs are.

The original fork and stem are chromoly and heavy. I want the smoother ride of a carbon fork and lighter weight.

I carry my bike a lot, so the lighter the better.

OK find a fork you like, and price the total cost, including a headset, and lower head cup adapter if that would be needed, then make the decision.

Given the other costs, and what you're likely to find, the 3ttt is sounding better and better, but that's your call.