Mega Construx, formally Mega Bloks, and Halo started selling there first toys in summer 2009 and at the time featured only 6 known sets that sold from an average of 12 dollars to 60 dollars per set depending on the set. The models where pretty successful in selling the original items so Mega Bloks, now under the name Mega Construx, continues to collaborate with Halo today featuring new Weapons, Combat, and Minifigure packs, model sets, Magnetic kits, and more to kids and adult who are able to build and play along with the vast universe of Halo
Now, fans continue to buy the products to collect more and more characters to display, or play with and to make their own stories and battles expanding the universe even further. The sets can basically fit any budget now with their smallest sets reaching to a price of only 3 dollars. Even if one person has collected all the sets Halo and Mega Construx has to offer in the current moment, some fans will get the same sets bought before again and again for their growing UNSC, Covenant, Flood, and various other armies
Not all sets can be found in every retail store selling Building Block toys and figures, Mega Construx has even released some very rare Minifigures and sets exclusive to a certain store. The most hard to find toys are featured for special occasions and promotions
It's an ever expanding universe that is doubtful to reach it's end as long as there still remains sets to build and games to develop