COTS: How far should it go?

[MrJohnston]

This is meant to compliment a similar thread - just adding a poll... "COTS" has come to stand for a huge variety (and level of complexity) of products. Is there a point at which we should set a limit for just how much "prefabrication" we can purchase? If so, where?

Here are some links to specific items that I'm including in the poll:

* Kit of Parts Chassis: http://www.andymark.com/AM14U3-p/am-14u3.htm
* AndyMark Intake System: http://www.andymark.com/System-p/am-3312.htm
* AndyMark Rhino Track: http://www.andymark.com/Rhino-p/am-3322.htm
* West Coast Products MMC Robot kit: http://www.wcproducts.net/mcc2016/
* AndyMark Dart Actuator: http://www.andymark.com/DART-p/am-3072a.htm