The DM64 pricing is definitely good, approximately 50% of the price of the BM235 + Edition from Welectron (shipped to US, in USD). The DM64 comes with covers for the probe tips, but not the banana plugs. Otherwise, they are similar in that you get silicone leads with gold plating and a carrying case.
I grew tired of Flir's web store overselling things and then days later claiming it was backordered. Ultimately I waited over a month with multiple extensions of the expected stocking date. So I've just been purchasing from their eBay store, which seems to be more accurate. If they have it listed, it will ship.
However, the BM235 & DM64 have some flaws, such as the small & stiff selector switch. Compared to the BM235, the DM64 seems a lot more stable on the bench and you can change the batteries very easily. But the case is hard plastic with a thin grippy coating, while the BM235 has more substantial and removable protection. So for drops I think the BM235 would win.
The DM64 also has some LCD modifications, perhaps to align it better with Flir's other DMMs. For example, the MAX/MIN/AVG are symbols instead, as is the EF function (very tiny icons).
But the innards are the same. I could not find any differences on the PCBs.
If you want a small DMM, my go recommendation is the Brymen BM20 series (BM22s, BM25s, BM27s). For current measurements, I suppose you could use 0.1 Ohms but that would perhaps be better with the BM22s which has a mV range. Otherwise you may want to add 1 Ohm for low current measurements. For example if you choose the BM27s.