Re: Izmir to Bodrum
Yes, most of the big bus companies have offices in Selcuk, but there are only one or two direct buses a day. Fine if you're staying in Selcuk, not so fine if you just want to change onto a bus to Bodrum.
More direct services ran before they build the motorway!
We've travelled with both Kamil Koc and Pamukkale in the past six months or so, and each time we were put on the dolmus to Aydin and advised to change there. Can't fault the service, but would not advise anyone to turn up at Selcuk 'on spec'. There are two buses a day that call into Selcuk and, if those times suit you, that's fine.