The Hulkbuster Smash-Up (76104) is a cheap set at Canadian $40 for 375 pieces. It's an ok fair price in 2018. It has a gear triggered right arm. The huge turning knot is at the back of this Hulkbuster. Maybe it is the reason why the shoulders are way apart from the body. Quite horrible when you look from the front... Like the arms are going to fall off. Lego set's "play value" is always a problem to many Lego model's shape.
The set comes with instruction booklet, 4 bags and a sheet of sticker. I think it is about the same as the hulkbuster from Age Of Ultron.
*I didn't follow the instruction fully in the first build.
When I open the instruction booklet, I study the structure of the gears inside the body and the arms. Because of the simple structure, I can change the shoulders easily. At the same time, I move the shoulders one stud out to make it wider.
The original legs are quite weird but.. quite impressive for the Lego designer to use less pieces to build the legs. I modify the legs into 3 sections instead of 2. I really like the original design of the lower part of the legs. I haven't touched the back of Hulkbuster because I don't even know what it looks like at this stage. All film photos and toy photos from Marvel are front view only.
I don't think I will spend money and time on buying the UCS version. It's all gone in every where.
