FYI, I tried HotSpot Shield today and it didn't work. www.hdtracks.com
simply doesn't load. It's quite an offensive piece of software in my opinion too. If you go to google.com it offers to 'disable google tracking' for you. If you agree it instead just sends you to there own search portal with ridiculous numbers of ads. After it's enabled I couldn't find a way to disable it, well, until I uninstalled HotSpot Shield which I did pretty quickly.
There's also cyberhostvpn which offers the same service, but I couldn't get it to connect to a US VPN server with the free version, only German ones which isn't much use in this case.
However they do offer a web based proxy service which you can select a US server from and it worked perfectly for me:https://cyberghostvpn.com/proxy/
Just put www.hdtracks.com
into the field, uncheck 'remove scripts' and 'remove objects', select 'US Server' then hit enter. You can then purchase tracks no problems. One thing I would do though is go to hdtracks.com outside of the proxy first and register your CC information with your account. Then go there through the proxy to make your purchase. That way the proxy doesn't potentially see your CC info. Though that may be me being just a bit paranoid