I'm starting at a high level and am able to use my gold to buy combined magic items for my starting equipment. How many items can I combine in this way, is it only two, or can I combine more? How much would the final item be if i can and did want to combine more?
Example:
Belt A costs 20000gp
Belt B costs 10000gp
Belt C costs 8000gp
Belt D costs 8000gp
In this example, how many of the items effects can I combine into one item, and how much would the finished item be?
You can combine as much as the GM permits. The price of the finished item will be 100% of the most expensive component plus 150% of each of the others. In your example, that's 20,000 + 1.5*(10,000+8,000+8,000) = 59,000gp for an ABCD belt.
Ask your GM. Any custom magic items are GM approval only.
The suggested formula is the additional ones cost 1.5 times as much (starting with the most expensive.) You can see that in action with the multiple stat belts.
Belt of Giant Str +2: 4000
Belt of Incredible Dex +2: 4000
Belt of Physical Might (+2 DEX, +2 STR): 10000 (4000 + (4000 * 1.5))
The suggestions don't list any maximum number, but any GM is free to find anything unreasonable. They are also fully encouraged to adjust the price if they think it is merited, the formulas are not the only thing to consider.
If approved the suggest price for your item would be:
20000 +
15000 +
12000 +
12000 =
59000
Personally, If I was your GM, I probably wouldn't allow custom magic items in starting equipment simply because it would be a lot to vet, not just for your character but all of the other characters. Being asked to consider a price now and again and if a given item is even going to be allowed is one thing, but having to look at several for multiple characters while trying to get a game going is another.
Thanks for the answers, just needed to know how it works.