Case production

[jimon]

However, for the same part milled from aluminum, it was $75 per part when ordered in 10,000.

And if it's 100-1000 then is it still 75-100$ per part ?

[Falcon69]

ya, the price goes up for less quantity, but at some point, you'll cap out. They can only make them so cheap, vs. cost of material.

Injection molding is so quick, but milling aluminum takes operator and machine time. Plus, cleaning of the aluminum after it comes out of the machine (there's gunk on it from the cooling process as the machine cuts it. 

Of course, with injection molding, there may be cleaning of edges.

Again, you just have to figure out how many you need. Would it be more economical to order what you need instead of spending the money for what the mold costs? Or is it cheaper to make the molds and have the parts injected molded?

[LabSpokane]

The pricing is very hard to quantify without actual models of all of your parts sent out for bid. What you want to tool may be cheap or very expensive. You also need to specify the life of the tool which can have a substantial impact.

The price of the parts will also vary depending on the material you wish to use. An engineering resin can be quadruple the price of polystyrene.

[coppice]

The price of the parts will also vary depending on the material you wish to use. An engineering resin can be quadruple the price of polystyrene.

Some materials, like polycarb, can be seriously expensive, but that isn't the end of it. Mould development for polycarb is usually way more expensive than for, say, ABS. People seem to go through multiple revisions before they come up with a mould that really behaves well, especially for clear polycarb.