Hi BigC,
The camera I bought in mint condition from Ebay. It cost £160 if I remember rightly, which was about half what you'd pay for a new DSLR body. Its the earliest of the Olympus Evolt series that has live view and built in image stabilization. Anything below an E-510 doesn't have the live view feature, apart from the E-3 which is the top of the line and costs a hell of a lot more than mine lol.
The lens is 20 years old and is fitted to the E-510 with an AD2 to Olympus 4/3 adapter. Its regarded as a "legendary lens" in terms of its sharpness/contrast/bokeh and it still holds its own against today's macros, which is why I picked one up. It generally sells on eBay for anywhere between £60-£90 depending upon condition. When you compare that to the digital macros which retail for £400, its a bargain. It takes photos at 1:2 ratio but with the extention tube it takes it to 1:1 life size. Due to the sensor size and crop factor on the E-510 any picture taken is twice the size of the 35mm standard, so even without the extention tube, I'm still taking pictures at 1:1 ratio anyway. With the extention tube I'm actually taking 2:1 macro shots! Its also a very fast lens with a maximum aperture of 2.5F, definitely not to shabby for a 90mm lens!
*Edit* The best macro lens for my make of camera is the Zuiko ED 50mm F2 Macro, which is about £400 and takes 1:2 zoom shots. There is a Zuiko ED 35mm Macro, which is about half the price but takes 1:1 shots. Its probably less expensive because the max aperture is 3.5F and from what I've read isn't quite as impressive optically as the 50mm.
Tamron make a digital version of the SP90, unfortunately I think its only for Nikon and Sony mounts.