My son & I started RC racing just over 3 years ago with the ubiquitous Tamiya TL01 followed by a TB01 bought from our LHS. At this time spares for these models from our LHS were plentiful and seemed reasonably priced.
We stuck with Tamiya's through the Evo III Surikarn onto TRF415's followed by TB Evo 4MS's and now TB Evo 5's. The problems started with the Surikarn which I purchased from Fusion Hobbies. The car was great but trying to get spares here in the U.K. was hopeless. Our LHS told us that the U.K. importers did not suppport the high end models as there was no profit in them. They made far more out of kids buying and trashing TL01's in their local Tesco's car parks than they did supplying a small number of parts to those wanting to race. As a consequence we resorted to the internet and, although a few model shops over here are now stocking items for some of the better Tamiya cars, it was so quick and easy to order from HK that we rarely order any Tamiya spares from the U.K.
If our LHS/UK suppliers can provide what we want we're happy to support them, after all it's not their fault we have to pay VAT etc.
In the past 10 months we've bought 4 1/10 electric off road buggies and 2 1/8 th scale nitro truggies from our LHS. We've also bought our Nosram BL systems, countless spares/hop ups, motors, wheels tyres, cells etc. both from them and other U.K. based model shops if our LHS did not have them.
The big advantage of dealing with our LHS is that you can do a deal with them which you can't do buying abroad. With our LSP truggies we didn't want the radio gear or the stock servo's. They gave us an allowance back againts these items helping to keep the cost down of the servo's and Spektrum receivers we wanted instead, which they fitted while I waited.
Basically the bottom line for us is that if our LHS can supply what we want or need then we'll happily use them but if we need to we'll shop abroad. We do however try and avoid ordering from the US as dear old HM C&E seem to take more of an interest in stuff from there than HK or Japan for some reason?