Fifteen Years of Digital

For fifteen years I have indulged in digital photography. For 10 of those years I have been using the same digital SLRs. Let's have a quick chronology:
2000 - a secondhand Olympus C820L purchased for a project then subsequently sold.
2001 - an Olympus C2020 - purchased for a summer working in Lumbier, Spain. It worked but not satisfactorily and was sold.
2002 - Nikon 995 - excellent camera that was used for a couple of years. It's packed in storage right now.
2002 - Nikon 3200 - excellent compact that inexplicably died in 2010. One day it worked, the next it didn't.
2004 - Canon S1IS - This worked until 2009 then died but the fault was a known recall issue so it was returned, fixed and I had it back. The photos weren't that great after the repair but the videos were OK.
2005 - Canon XT. I'm still using it. 8 megapixels. It's not the latest but I have noticed no lack of capability even though later camera systems are smaller.

While my cellphone takes excellent images, it lacks in low light photography. It is however the camera of choice because it uploads instantly, ready for use online.

This is a cellphone image. The first image was from my XT. There's not very much difference. The XT image has an edge but to be honest, the difference in image quality is easily trumped by the ease of use of the cellphone.

What does the future hold? Who knows? I know I want to take more night sky photos but better than this. The Tamron 17-35 lens used for this photo was tragic in terms of image quality. The corners have been described as "softer than last night's mashed potatoes". I sold that lens.

There are but two ways forward in order to take that kind of photo again. I could get a lens to replace the sold 17-35. To get decent optical quality the lens would have to be a prime. Thereby hangs the problem. A 12mm Rokinon lens would be the cheapest but at $450 new, price rules it out. Secondhand would be better but it's not a lens that would hold its value so there's another reason not to buy new. I assume the poor resale value is why none are available secondhand.

The alternative would be to get a different camera to use with my existing F4 lens. I'd need to gain at least an extra stop or maybe two. Star photos are normally shot at EV-6. It just seems nuts though to spend $400+ on a new camera when my XT works perfectly well.

A different way forward would be to use a more compact micro four thirds camera with lens. Secondhand that comes to a much more reasonable $150. The questions are whether I'd want to spend $150 in order to take a specific kind of photography or whether I'd want eventually to change systems to micro four thirds. It's an interesting thought that'll probably not happen due to my current priorities lying elsewhere.