My point was that a <10k limit is apparently at least somewhat common in electricians tools, so there must be a market for it, they could easily have skipped the resistance function or increased the range. I don't believe that it's just to sell more DMM's, plenty of people carry just a T5 for troubleshooting industrial stuff. Whether it's suitable for this price class, I don't know, I'm not that familiar with clamp meters.
From a quick look at the Fluke line-up, the Fluke 32x has resistance up to 400ohm, 333 up to 600ohm, 334-337 up to 6kohm, Fluke 902 (marketed for HVAC) 10kohm, so 4kohm doesn't seem very low. It seems that they don't even have a clamp meter with full DMM ranges.
My guess is that many electricians (excluding the HVAC crowd) don't need more than a few kohm. I agree that it probably doesn't cost an extra $100 to add the higher ranges (not sure what the other extra features of the U1213A are), that's just product differentiation. Everybody does it, it's not like it costs Fluke that much to drill a few extra holes and put in a few extra buttons.
Don't hesitate to complain to Agilent that you need more than 4kohm for your work.
I really don't see the point in the 77-4s existance, you might as well buy a 175 or a 177, and they're cheaper!
I'm not sure either, it looks just like a 175 with a few buttons less, so it's not even any easier to use. The 11x series have replaced the 7x series as low-end electricians/electronic troubleshooting meters, and the 17x is better in almost every way (except that it's really slow to respond). I believe that Fluke introduced the 77-IV at least a few years after the 175/177, so there must have been demand for them.