Well what i am saying is that as you have spent $50 on your setup be happy that your little friend is budding happily. You will not get monster nugs but you should get the same quality smoke as anyone else, and prob 0.5-1 oz dry if you are lucky (depending on how dry is dry to you - we arent measuring Hearson Oven Volatiles here to test moisture content!). The only thing 'wrong' is that your lights are not great.
But then consider the following:
http://www.biologie.uni-hamburg.de/b-online/e24/3.htm
http://mhl.nsw.gov.au/projects/berowra/chloro.php
https://www.myosram.com/sap/its/mimes/zisaglobal/99/asp/omd/cz_ecz_030.asp?bildId=333891&Path=broschueren\&res=hires&typ=pdf
http://en.wikipedia.org/wiki/Photometry_(optics)
http://en.wikipedia.org/wiki/Luminous_flux
Link 1 tells you that the optimum light wavelengths for most 'normal' plant absorption are 430 & 450 nm (blue), 640 & 660 nm (red), though plants will use the green-sensitive carotenes/chlorophylls to produce energy via a less efficient mechanism (link 2).
The 3rd link is to the Osram PlantaStar bulb, a colour adjusted HPS bulb to provide better growth (blue light - you can see the small blue bump on the spectrum on the second page). Note that most of the light for the HPS is emitted between 570-640nm. So, compare that spectrum against the spectra on the first and second links and you will see that a lot of light is wasted. This is compensated for by the fact that the HPS bulb outputs a LOT of light. Also note the luminous flux values (32000lm for a 250W bulb) and compare them to the typical fluorescent - about 1500lm at 25w. If you had 10 fluorescents you would have about half the perceived light output of the HPS, and this is true - a HPS has about 150lm/W efficiacy (the term for electricity -> light efficiency) and the fluorescent has about 75lm/W.
To complicate matters the measurement of lumens is misleading due to it being a measurement of light intensity as perceived by the human eye (see the last 2 links), which gives far greater weight to the green colours - exactly the opposite of what a plant sees! This effectively reduces the massive number of lumens (for some kind of incorrect comparison) to something perhaps more comparable to a Grolux fluorescent (see previous post) that has about 60% of the lumen output of a cool white fluoro but is almost perfectly spectrum matched to the absoption spectrum of plants (a high PAR - Photosynthetically Active Radiation - value).
You could add LEDs in the mix but they have to be pretty much bang on the peak wavelengths of the plant absorption spectrum or they will fail spectacularly (as many people have realised after buying lovely 'Red' and 'Blue' arrays!), as LEDs generally only emit light well over a 20nm range.
The long and the short is no artificial light source is perfect (
the Gravita Pro 300 LEP?) for plant growing and the choice for everyone is based on many factors (PAR, overall intensity, room size, heat build-up, fire risk, cost (initial and running) etc). So as i say things look like they are going fine for you, and it is all a learning curve. Just stay chilled, go with the flow and enjoy it and i'm sure things will work themselves out in the end - they always do!