Have you considered renting lenses? Prophotorental.com in Boulder offers fair prices with minimal deposit. I've rented a number of gold-band lenses from them over the past year and always had a good experience. The 105mm f2.8 macro is hands down my favorite Nikon lens so far. It's tack sharp and built like a tank. Hope to have one someday.
Camren in Denver is also pretty good. About $26 a day for lenses. Kimo, aren't you shooting macro now? The flowers above mine in your last post are surely pushing it, that DOF is insane!