Components

Well if it's CARDS, Dominion has 500 cards (I learned that this week). I have seen the game be played, although I have never played the game myself. True Kid also related to me the MSRP of Dominion is $45.00.

From a personal level, my own game would have 364 components for a four (4) player game.

So I think 250 components is NOT too many. I am assuming that your game is for four (4) players... And if it is, well I think you are within reason regarding the components.

If you are using plastic or wooden parts, the weight should not be a factor. Perhaps if you were using miniatures that were made of metal, maybe if you used a lot that would be heavy. I think ONE factor regarding weight is the 60 pt Chipboard (playing board) which is the size of a Monopoly board might be the HEAVIEST element in a game. It's fairly large and somewhat heavy.

Custom parts are probably EXPENSIVE. Same with custom dice... I think it comes down to a question of moulds and the one-time cost required to make one.

Depends on how you're going to use the components.

If you're planning on placing and using all 250 components, it may be a little too excessive. But as one poster said, it may work for you if you're building a game that's meant for extremely deep gameplay and strategy. Games like Eclipse and Arkham Horror are great examples of this.

Then there's the other extreme where you have a large amount of components, but not many are used for the game to account for high replayability. Betrayal at House on the Hill is a great example of this. Pathfinder Adventure Card game has about 400 cards, but only like 100 are used in any given game.

But if you want just straight advice, I'd say: Keep it Simple Stupid (K.I.S.S). If you're putting in components in for components sake, it's probably not wise. Simplify if you can, if you can't, that's ok.