Assuming it's true, and not another "source: trust me, bro" pulled out of arse statement from the all reliable Defseca (sorry for any Defseca people watching), here's my opinion:
Bangladesh should've stuck to the Mi-28s from the very beginning instead of daydreaming about the most expensive attack helicopter ever sold (AH-64E). Mi-28's are a far more cost-effective option for a country like Bangladesh, which happens to also operate Mi-171s that share similar components.
The Mii-28 is an incredibly rugged piece of machinery. There was a famous magazine article of a US pilot's impression of flying the Mi-28 back in the early 1990s (when Russia opened up for these things), forgot the name of the US-based magazine. He said it was the most rugged machine he ever operated, yet it flew more precisely and with more agility than any rotorcraft he have ever flown, of any class. Bear in mind, thanks to its heavy armor and rugged airframe, the Mi-28 weighs about a ton more than a Mi-17 cargo chopper (empty weight).
The Mi-28 and the apache were originally designed for slightly different styles of fighting. The mi-28 was more of a close-in brawler using its heavy armor (by far the most armored rotorcraft in history) to get close to the troops and provide close air support, using primarily its very powerful shiponov autocannon (much more powerful and accurate than the apache's chain gun) and rocket pods. For anti-tank roles, it was initially equipped with Shturm anti-tank missiles, and then ATAKA, both Soviet-era laser-guided anti-tank missiles. They do the job just fine for the sort of battlefields they envisioned fighting in, namely huge, relatively flat planes of land
The Apache was more of a dedicated anti-tank vehicle. Because NATO had to face the overwhelming numerical superiority of Soviet armor in the cold war (they still do now). So they placed a higher emphasis on dedicated anti-tank platforms. The Apache initially fired laser-guided hellfires, which are very similar to the ATAKA missiles fired by the Havoc. The Apache however has very thin armor, it's barely more armored than a Blackhawk. It's really not designed to take many hits, at least not as much as the Mi-28. So it relied on picking off enemy tanks at a distance. Its closed air support capability, by getting as close to the troops as possible, is more limited than the Mi-28.
The Apache-D was the next evolution, with the introduction of the millimetric radar and radar-guided hellfire missiles. That introduced a whole new capability such as all-weather effectiveness (radar waves aren't as affected by weather and low light as laser), as well as locking on and firing at a target that's not within the line of sight. So an apache can hide behind a row of trees with only its radar showing, take a look at the battlefield, identify the most critical threats (it's the advanced computer that does this automatically), and lunch radar-guided missiles at them simultaneously. Arguably the no-1 best feature of the apache weapon system if you ask me. This is something the Russian's did not have until recently, mostly because there wasn't really a need for such capability for the sort of conflicts they envisioned.
The Apache-E is the final evolution, upgraded engines, new data integration and management systems, improved hellfires, and ability to control UAV/UCAV's. But a lot of that capability, especially the net-centric ones, are pretty much irrelevant for a country like Bangladesh which BARELY has a modern military for it to work in synergy with.
The Mi-28 also evolved a lot throughout the years. It also received a top-mounted radar (N025 or N025E downgraded export model). The ones designed for domestic use only for the Russian armed forces are in my opinion the most capable and overpowered attack helicopter on earth. It's packed to the brim with the sophisticated electronic warfare system fitted to a rotorcraft (I suggest reading up on Russia's EW and ECM capability, it's an area they have a massive body of knowledge on which even exceeds the west). It can also HERMES fire and forget anti-tank missiles with over-the-horizon capability (just like the latest hellfires). And it outranges any hellfire variant by a considerable margin. But sadly, these features are not offered for export. Russia will keep its most advanced technologies to itself.
I'm not sure what the weapon packages are on offer to BD, but I suspect it'll be 80mm rocket pods (we already have them for Mi-171s) and ATAKA ATGM's, or possible AT-15 Khriizantema, which is a very capable dual seeker ATGM with a humongous warhead.
Both helicopters possess much more capability than what the Bangladesh army/airforce can be expected to extract for them, but the Mi-28 is SUBSTANTIALLY cheaper. People also need to realize the nature of US defense companies like Boeing and their subcontractors to understand just how bloated the cost of their equipment is. Just cuz they are much more expensive than the equivalent Russian or even European hardware doesn't make them better necessarily. Russian gear is cheap bc low labor costs, full technological autonomy (they don't rely on technology or parts from other countries as US companies), and not having such a complex internationally spanning supply chain as US companies.
Also bear in mind Apache's are notorious hanger queens. They need a lot of pampering and care to get them running in tip-top conditions. I know people say Russian choppers crash blah blah blah, but more Land Cruisers break down than Range Rovers, despite being a million times more reliable. Simply because they're deployed more and see the roughest actions. Even the US admitted in Afghanistan, where Mi-17s conduct missions initially set for the likes of their Blackhawks and chinooks.