Bandai Robot Damashii or Robot 魂 entry for the Full Metal Panic series arm slave ARX-7 Arbalest, perhaps is one of a solid action figure mecha and yet affordable compared to the Alter Mechanical Model ARX-7 from my previous entry.
Alter ARX-7 Arbalest from the anime Full Metal Panic! The Second Raid is a Generation 3 arm slave with an experimental Lambda Drive. In the story the Lamda drive gives supernatural abilty to the arm slave, making it a 1 man army.
Alter has replicate this iconic mecha from the series with very high detailed in 15cm or about 5 inch action figure.