Making a custom construct seems to be very complicated in general, although it's pricing is quite simple - CR squared x 500.
Then I thought of a simpler way to do it by taking a regular monster and basing the construct off it. My question is, is this a simple way to design and price a construct that follows the rules?
1) Pick a monster with just racial HD
2) Apply the construct type with all its attendant statistics as if applying a template i.e. change HD to d10s, remove CON, add bonus hp dependent on size (+20 for medium for example), remove any good saving throws, add fast progression BAB, darkvision, low-light vision, construct immunities etc
3) Choose where to put skill points (if it has an Int score) at 2+Int per HD, minimum 1.
4) Choose feats according to its HD (if it has an Int score) - presumably you can choose from monster feats when doing this.
4) Increase base creature CR according to its special abilities, the first one is free and the others are 1/2 to 1 CR each
5) Total up the final CR of the construct & work out the price.
I too am interested in this.