There is one real advantage to buying a kit--you can start as soon as it comes. I just searched google and saw a kit (from a company I never heard of) for under $30 US. Electronic Goldmine (which I often use) has a kit for $45.

If you get the parts and are still enthusiastic when you get to about lesson 8 then start buying the parts for the other lessons so that by the time you get to 12 and on you will have the parts.

I'm about to unleash the ire of many on this list, but I recommend the Chinese sources which ship free and take several weeks. I know that many people have found they got counterfeit parts, but you are going to be buying, usually, collections of parts that are too cheap to bother counterfeiting--100 assorted color LEDs for example or 10 each of a full range of 1/4 watt resistors, or a 50 pack of asst. electrolytic caps.

 

parts that are too cheap to bother counterfeiting

When you're living on a couple dollars a day, what is to cheap to bother with? I've seem pictures of piles of SMT caps that were being salvaged from discarded boards.

Once counterfeiting became so rampant, the bulk of my purchases are from authorized distributors. It's not worth saving a few dimes to have rejected/relabeled/counterfeit parts that increase your debug time significantly.

I buy wires, connectors, and tools from China. Most of the knock off tools are good good enough, and I save many 10's of dollars on each one. I bought a PEX crimper for around $10, with free shipping. The authentic one I bought at Home Depot cost $130; but a fastener (special one) came off and was lost, rendering the tool useless...