PCB Design vs Cost

In an effort to reduce PCB cost I'm looking into different PCB design methods.

1) Does pad shape determine cost? Example, for IC's, do oblong pads cost any more or less than regular round pads?

2) Does a board with through-hole vias cost more than a board without them?

Pad shape does not effect cost.

Through hole is an extra process that costs.

PCB design cost on the dense of the PCB not depend on via and Pad.

The price mainly depends on size and number of layers, less on minimal feature size. Then you have the rest of technologies like buried and blind vias, gold plating, microvias, embedded components, you name it.

Regardless of whatever else you do a real savings can be had by reducing the size of board by using SMD parts.

Burried and blind via's will cost more. If your making 1-10 things would be different than 10,000.
In the prototype stage, there will be a set of design rules. There might be a fixed cost and or a cost per square inch.

Some design rules are.
No blind or burried via's
2 Layer
X far from the edge
Square boards only or more common No internal cutouts
Single design per job
Minimum hole size
minimum track width
minimum spacing
Hole density e.g. Holes per square inch.
Silk screen on both sides sometimes cost more.
How fast the turn around is
Electrical testing: (sample or all)
Max size
No Gold fingers

Production:
The number of holes will matter.
Electrical testing will matter.
The density can usually be larger.
Blind and burried vias are possible.
Thickness of the board and color and type of material are now chosen.
The number of layers can approach 40.

You can also look into services where the board is assembled and components are sourced and placed by the PCB manufacturer or some are and some aren't.

Single sided is more likely in production quantities. The process is primarily geared toward 2-sided with plated thru holes. It's wise in any case to put via's away from IC pins.

Here is an example of blind and burried vias: https://en.wikipedia.org/wiki/Via_(electronics)