Parts Prices (In US Dollars)

Here is the analysis I have done so far. I didn't look everywhere, but I did learn 2 things.

1. You can't buy everything from 1 place
2. It is cheaper if you buy from outside of the US on some parts

Here goes my summary: (For all intents and purposes, when priced in £ double it for US dollars. It is a bit less than double, but after your credit card company charges a fee to convert the purchase it will be close to double given the current rate of exchange on 5/7/2008)

Starter Pack (Picaxe 28 with USB cable)

•  TechSupplies £25.61 $51.22
• SparkFun $63.90 (USB cable purchased seperately does not come with a cable. Is cheaper if you buy the serial.)

Motor Driver (won't need right away, but get it anyway) 

• TechSupplies £3 $6
• SparkFun $2.35 (Note: This chp is different than th eone above, but is a pin for pin replacement meaning the usage is basically the same.)
• Pololu $2.95 (Note: Same as above)

Servo Upgrade

• TechSupplies £13 $26

SRF05

• HobbyEngineering $29.99 (can get cheaper models, but given how people like this one in terms of distance the slightly extra cost is worth it)

Gear Motors (Motors and wheels)

• HobbyEngineering $11.69 (if you buy 2-9, but why would you only buy 1?)
• Pololu $9.45 (note: The link is for the motor ONLY ($5.95), the wheel is $3.50 additional)
• Solarbotics $7.98

Gear Motors (Motors and tracks set of 2 to make 1 robot)

• Solarbotics $39.95

28x Picaxe Chip (I got an extra for my breadboard. The kit DOES come with 1.)

• TechSupplies £4.35 $8.70
• SparkFun $11.95

LEDs (You can buy these at RadioShack but for a dime each (after conversion to dollars), buy them here since RadioShack is 2 for $1. Besides you will burn these.)

• TechSupplies £.05 $.10

Voltage Regulator (if you will use a battery pack of 4AAs you probably won't need this, but if you want to use a 9volt get one or two)

• SparkFun $1.25
• HobbyEngineering $1.80

You can also order resistors from these places, but 5 for $1 I got them from RadioShack. I knew I would need 330OHM (for LEDs) and 4K7Ohm (for the processors if using a larger battery) so I bought those cheaper at the above websites. Others buy when you need them.

Notes:

• I got my breadboard from RadioShack because I forgot to look on the websites for one.
• WATCH THE SHIPPING ON TECHSUPPLIES! One pack of resistors can make shipping jump FAST!
• On TecSupplies website less than £10 of items cost £4.50 to ship. As weight increases it jumps from £12.50 to £19.00. If you shipping is £19.00 see if you can cut your order down a bit to get cheaper shipping. It may be worthwhile to buy an item elsewhere for more $$$ to save on shipping.
• All BOLD text is cost in dollars.

If I made any mistakes or if people find the same stuff cheaper let me know. My goal was to cut this down to ordering from 1 or 2 places.

 P.S. For those worried about paying sales tax here is the country and state of origin for the companies:

TechSupplies - UK

SparkFun - USA, Colorado

HobbyEngineering - USA, California

Pololu - USA, Nevada