No worries Vikram,
Hmmm, I just had a look it's still listed on ZWO's site but, agree, doesn't appear anyone is selling them here.. very interesting. You can order from ZWO direct, they will ship to Australia if you want to see if you can get one.
https://astronomy-imaging-camera.com...asi294mc-color
If you are looking at sensor size as one of your primary decision points, you might look at the 183MC perhaps. Not a 4/3 sensor but, a full 1" so, not quite as big but, no as small as the 224 or 290MC's. Another option you might consider is an f3.3 reducer; they will come to focus with these ZWO camera's but, not with a DSLR...
As someone else said, make sure you keep a close on the classifieds here, there are some gems come up at very good prices... just be cautious..
Regarding where you purchase from & their prices.. I've bought plenty from Sirius Optics, they are great people to deal with but, not always the cheapest for everything..
Make sure you have a good look at BINTEL, Astro Anarchy & despite their 19th century website, take a look at Andrews Communications. You might find that you can get some or all of what you are looking for at a cheaper price. If it's only the odd item from your wishlist then, you just need to weigh up the postage costs if buying from different suppliers...
The other thing to think about is if you are buying it all in one go, perhaps one of the retailers will do you a package price... it pays to ask each of them... they want your money, maybe they will do you some deals..