Ok. It seems I didn't *quite* understand what was being patiently explained to me (not for the first time, I hasten to add!), or rather I ommitted a very important detail. This is the first time I've used the points-buy system so please forgive me while I don my trusty brain crampons and climb the learning curve. Bring back dice, all is forgiven!
Racial bonuses/penalties are applied prior to adding points. So, if you have your elf with his +2 Dex bonus he goes up to a starting Dex ability score of 10. If you have your half-orc with no Dex bonus his starting Dex ability score is 8. Simple enough so far.
Important bit: Whatever the bonus/penalty is, it then translates to a positive or negative modifier to the points cost. Still with me? Then you're a better man than I because I had to have this explained a good ten times before the penny dropped.
Basically, if you have a -2 Dex racial penalty, you apply this to the relevant ability score before you buy your points and you translate the penalty to a +2 bonus modifier on the points cost. If your elf has a +2 Dex racial bonus you apply this before you buy your points (so he has Dex 10) and you translate the bonus to a -2 penalty modifier on the points cost, then you buy your points. If it was a -1 or +1 racial bonus/penalty you'd translate it as a +1 penalty/bonus modifier respectively on the points cost, and so on and so forth. You apply the modifier, either as a deduction or addition, whether you go above 14 or not.
Extra points costs still apply if you lift your ability score above 14. The crux of all this is that an elf who starts with a Dex score of 8 and pays 8pts to go up to an ability score of 15 doesn't then get an unfair advantage over those with no racial bonus if he adds his racial +2 bonus to lift Dex to 17 (which should cost 13pts). Yes, the elf should have a +2 advantage anyway, but using this method his advantage is greater. He is in effect an ubber elf!
The 8 point starting level is the default zero cost. So if you have a racial penalty, -2 Con for example, you start with 6 points instead of 8. The cost of adding 1pt to 6 to bring your Con up to 7 isn't 1, but -1 because 8 is default zero. -2 Con is a racial penalty, so it translates as a positive score modifier of +2. -1 + 2 = 1.
If you think all this is confusing, you're right.
If you are a bit flummoxed, ignore all the above and just do this:
Start all abilities at 8. Add any racial adjustments. For positive racial adjustments (ie +1, +2 etc) deduct the equivalent amount from the cost of buying points. For negative racial adjustments, add the equivalent amount from the cost of buying points. Use this sliding scale.
Ability score Cost
6 -2
7 -1
8 0 (default zero points cost)
9 1
10 2
11 3
12 4
13 5
14 6
15 8
16 10
17 13
18 16
And let me know if you have any problems understanding what the hell I'm talking about.