For a simple price it is sure a worth while thing to get for people who like making their own rpgs. the one thing i do enjoy is that it is not just for futer mechas, it even has ways to make old midievil type crafts. some of its draw backs is that it dose go on and on and on at times but that is sorta the thing you find in these books.
D20 Mecha is great for beginners or peole who are stumped with making RPG's this book explains on how and why to limit certin things with great detail. it also helps you with value of things, point systems, character creation, and an idea of a direction to go.
now some of you probably think "i do not like d20 system so how is this good for me?" well it also has a guild for every dice system not just D20 and also any currency you wish. now it is not a bible of how it has to be but it is a good thing to have next to you. all and all i belive it is a worth while buy.