Firstly, on-topic, I would generally not "reinvent the wheel", unless an off-the-shelf module is too expensive, too hard to get hold of or could be hard to repair or replace in the event of a failure. Yes, I avoid those "chip under a blob" modules.
Yes, I do try to "support" Maplin, but some prices do appear rather high. However, I was quite surprised to discover that it's still possible to buy a single resistor of any value (or a Zener in my case) from most of their shops, at a reasonable price. Rather worryingly, the last few times I've visited my local store, the customers have been outnumbered by the staff.
In Australia, the high cost of labour and retail display/storage space are a major part of the cost of electronics components sold to hobbyists. Small transactions are likely to produce a loss to the business but suppliers have little option - a surcharge for transactions under a threshold is not good for business in the hobby world. I feel guilty if I have to go to a local components retailer and spend only a few dollars.
I'm in business in a niche market where I design and manufacture specialist electronic devices under contract for clients. The cost of components can represent only a few percent of the project's cost. I carry a 'stock' of most of the common components, running into thousands of dollars. Even then, I will spend thousands on components annually. At least the retailers know me and also know that I put a lot of business their way.
Also, I was sad to see that Dick Smith have "disappeared" from Australia/NZ. But, I did fail to find what I had wanted in one of their stores a few years ago, so it seems the rot may have already set in then. I refrain from using the term "decline", because I gather their failure was due to excessive (unjustified) expansion.
The Dick Smith business imploded in the last couple of years due to bad management and, reportedly, asset stripping in a business sale deal. They started out as a hobbyist component supplier in the 1970s but then diversified into consumer electronics. The higher unit profit for audio, TV, computers, games and phones seduced them away from hobbyist components. They had not sold components for about five years prior to their demise. The highly competitive consumer electronics market, with the advent of on-line marketing, signalled their demise.
In Australia, we are lucky to have healthy networks of national and international suppliers of electronic components. My preferred supplier is the locally based national supplier, Altronics, who conveniently sell many PICAXE products. For specialist components, I have to rely on the international buying power of Element 14, RS Components and Digikey. On the world stage, Australia's market plays a pretty small part.