I realize this thread is now 2 months old but ...
The problem with "prototypes" and "one-offs" is they are expensive both to the consumer and to the PCB MFG. Many PCB houses that do prototypes do them so they can ultimately get production quantity orders ... a few actually specialize in doing prototypes and short runs. I am unaware of anyone who willing populates boards for quantities < 5k units. You can get prototype PCBs made in the US or in China, and pricing for 5 * 3" x 5" x 0.065" PCBs could range from as low as [imath]20 to over[/imath]500 ... outsourcing PCB population could easily add $100 or more to each PCB and push lead times ridiculously far into the future.
There are several methods of making DIY PCBs, each with its own quirks and pitfalls. If the PCBs are single sided your chances of DIY improve tremendously. Toner Transfer is probably the most popular DIY approach, though I have had better luck using pre-sensitized PCBs and a transparency. I have just had too many problems with the Toner Transfer method, but, lots of people have had very good results with toner transfer.
If you have a friend with a CNC router, I use one to make all of my prototype & short-run PCBs ... I can cut traces down to ~10mil with ~10mil spacing, in 1/2oz copper (1oz or thicker requires a bit more spacing because I use a "V-Bit" and the deeper it goes the wider the space) ... where possible I prefer to keep my traces 20mil to 40mil (aiming for 10mil spacing here is fine in 1oz and up copper it just makes a 20mil trace closer to 18mil).
I have cut several hundred PCBs that use a PT4115 LED driver chip that has an SOT89-5 footprint (whole chip is 4.5mm x 2.4mm, pads are 0.5mm (20mil) with 1mm (40mil) space between them with very good results, but attempting to cut traces for something like the ATMEGA u-controllers that have 0.2mm (8.6mil) pads and 0.5mm (19.7mil) pad spacing is beyond my machine's capabilities (not to mention difficult to solder manually).
Not sure if any of this helps, just thought I would enumerate some DIY options.
While there are DIY processes for tinning, solder masking and silk screening boards, I don't typically bother with anything other than tinning, and I do that with a soldering iron and solder rather than chemically. Occasionally if I need writing on a single sided PCB I will print it on paper or a transparency and glue it to the top side before I cut/drill it, or I will print what I need on a mailing label and stick to the PCB after it is cut and drilled and then just use a needle to punch through any holes it covers up...