As stated, the most economical option is a Chinese thread mic. Shars and others sell them for a price that is a fraction of a Tesa or Mitutoyo or even a Fowler set. All that I have seen come in sizes like other mics do - 0-1", 1-2", etc. The Shars mics each come with a set of anvils that can be used to measure both Imperial and Metric pitch diameters; no need for metric mics like other makes require. Cost is very reasonable for what they are and especially when compared to the Swiss or Japanese mics. The Shars mics are calibrated in tenths, not thousandths.
To put cost in perspective, just the calibration standard for my Tesa 0-1" mic would pay for the first three Shars mics so an Import is the way to go unless you're really well heeled or get fabulously lucky on ebay. I used to use a Fowler (Chinese) mic and it was as accurate as my Tesa mics (I think).
Personally, I would not go with individual mics that don't have interchangeable anvils. They work but costs are very high for a complete set if you buy new.
We all have different experiences with these things. I find thread mics faster, simpler and easier to use than thread wires, especially when checking fits while the part is on the lathe. I haven't used my wires in years and am happy not to do so.