dezuman,
I mainly only concerned with the hardest items to find in a recipe. The top three things in my experience is Diamonds, iron (because IC is very iron oriented), and coal (because it can either be turned into diamonds or it is needed for fuel, breeding, carbon plate, etc) in that order. So if I counted everything right for my low cost 0 chamber mark I you need 20 iron and 20 advanced alloy for the reactor. You then need 6 iron and 6 advanced alloy total for the 4 dispensers and the 4 platings. So in total for the whole thing including the advanced alloy that is 56 iron or if you have a macerator that is 28 iron ore. For a single advanced solar panel you need .5 advanced alloy (or 1.5 iron), 24 coal, 1.125 diamond, and 2 iron. For three of them and rounding up that is 12 iron (6 iron ore), 72 coal, and 4 diamond. Not to mention with the reactor you will still get an addition 400,000 EU over the same time. So yes in my opinion the reactor is cheaper. My mark I reactor also requires no maintenance (no component degradation) so all you have to do is send 2 seconds every 8 days to put fuel in, hardly a big issue.
I do concede the point that it takes up more room. However it generates power underground and it can be upgraded to make even more power since the water tank and power lines are already set up. Like I said I m not getting into the whole advanced nuclear reactors and breeder thing. If you have that kind of a setup A) you should be getting a lot of power (unless you designed your reactor wrong) and B) should have an almost infinite supply of fuel with breeders (which means efficiency no longer matters and your reactor can go for more power). The only downside is that you have to play switch the cells around every 8 days, but the power should more than make up for that.
I m not going to get into SMP.
RE: Edit: The conversion recipe costs 5 less coal, something like and .125 less diamond however making the cheapest solar panel still adds and additional 6 iron to the cost not mention the extra pain of making those 4 extra recipes (battery, furnace, iron furnace, generator, solar panel, vs just making glass fiber cable)
RE: Edit 2: The more EU/t would come at a cost of having a HV infrastructural. It would generate 16 EU/t but then even one advanced solar panel would require that you attach it to a MFSU (the batbox or MFS would blow up if attached). This means you have to add the cost of making an MFSU and using either HV cable or glass fiber cable to use advanced solar panels. This is actually the way I m leaning if there isn't an out cry of comments against it.
As far as 11 solar panels vs. 1 advanced solar panel: 11 solar panels would cost 66 iron (33 iron ore) and 33 coal, 1 advanced requires only 4 iron, and 24 coal (however you have to do a lot of processing on the coal and iron which means you will be spending a lot of EUs and a lot of time on them), and also you will need 2 diamonds. I think it works however again I m open to comments and if the majority want it to be a higher cost then post and let me know. I m not out to break the game. I just don't want to have to craft hundreds of solar panels.